The trial ended prematurely and the case must be tried again, because the verdict is contrary to the evidence of both parties and is supported by the evidence of neither. The evidence presented during the trial contains few contradictions and raises only two main issues of fact —whether after revoking their acceptance of the camper plaintiffs later withdrew their revocation, and whether plaintiffs are entitled to recover either actual or incidental damages of defendants —and it is both incongruous and erroneous that the trial ended before any of the matters really in dispute were determined. For defendants’ evidence, as well as plaintiffs’, shows clearly, unambiguously and without contradiction that plaintiffs revoked their acceptance of the camper within a reasonable time after learning the engine was defective, and the verdict to the contrary should have been set aside, as plaintiffs moved. Leaving aside plaintiffs’ evidence, in pertinent part defendants’ evidence relating to their breach of warranty and plaintiffs’ revocation of the purchase was that: On 27 July 1984 the Whitehursts bought a new Coachman Camper from defendants for $33,208; Coachman Campers are made to live in while traveling from place to place and defendants knew that plaintiffs bought the camper for that purpose; the vehicle had a new Chevrolet truck motor, which General Motors warranted and the corporate defendant stood behind; on 28 August 1984, just 32 days after defendants sold the vehicle, plaintiff Norman Whitehurst complained to defendant Crisp about the motor not running properly and being defective and demanded at that time that the sale be cancelled; defendant Crisp told Whitehurst the problem with the engine might be minor and correctable and that he should have the engine examined by a Chevrolet dealer qualified to do warranty work on Chevrolet engines and if the engine was not up to the warranty it would be corrected; two days later plaintiffs had the engine so examined, at least to some extent, and that very day plaintiffs’ lawyer notified defendants in writing that the purchase was being rescinded and the vehicle returned to defend*525ants’ place of business because, according to the mechanic that examined it, the vehicle engine was seriously defective. Upon receiving this letter defendants had their lawyer write plaintiffs’ lawyer for permission to have the engine more thoroughly inspected by a Chevrolet approved mechanic and had their lawyer to find out, if he could, whether plaintiffs would accept a new engine if the inspection showed that the one in it was not repairable, and would accept the repair of the engine if the inspection revealed that the defects were minor and repairable; defendants received permission to have the motor inspected and after the motor was dismantled and thoroughly inspected General Motors, the maker of the warranty, recognized that the engine was not repairable and had it replaced by a new engine under the warranty-

The foregoing evidence, which is neither ambiguous nor contradicted by other evidence, clearly establishes as a matter of law that plaintiffs revoked their acceptance of the camper in a timely and effective manner in full compliance with our law. Leaving aside the evidence of plaintiffs’ attempt to revoke the purchase on 28 August 1984 when the motor first failed to perform satisfactorily, this evidence shows that plaintiffs’ revocation was initiated no later than 30 August 1984, only two days after plaintiffs first learned that the engine might be defective; for it was on that day that their lawyer wrote defendants that the sale was being rescinded and the camper was being returned to them. And it is equally clear that the revocation was completed a day or two later when defendants admittedly received the letter. G.S. 25-2-608(2). Although whether the acceptance of a purchase has been timely revoked under the Uniform Commercial Code is usually a question of fact, when the facts are undisputed and only one inference can be drawn from them it is a question of law for the court. Maybank v. Kresge Co., 302 N.C. 129, 134, 273 S.E. 2d 681, 684 (1981); see also, Adler v. United States, 270 F. 2d 715 (8th Cir. 1959). Returning the vehicle purchased to the defendants, notifying them in writing that the purchase was rescinded because the motor was defective, and demanding the delivery of a new vehicle or the return of the purchase price can only be construed as being a revocation of acceptance, in compliance with G.S. 25-2-608. And mailing the written notification of revocation to the seller within two days after the engine first failed to perform satisfactorily and *526on the very day that the purchasers were advised by a Chevrolet mechanic that the engine defect was serious can only be construed as notice made within a reasonable time under the provisions of G.S. 25-2-607(3)(a) and G.S. 25-2-608(2). That the jury found otherwise was due to the confusing and inconsistent instructions that they received from the court, as the record plainly shows. Instead of peremptorily charging the jury on this issue, or even charging on the issue separately, the court intertwined its instructions with instructions concerning whether plaintiffs withdrew their revocation and in doing so charged on a multitude of alternatives to the resultant confusion of the jury, as their requests for clarification attest. One alternative erroneously charged on by the court was that plaintiffs’ acceptance of the vehicle might have been revoked by filing suit, which was more than three months after the camper was returned to the seller and defendants were notified in writing that the purchase had been rescinded.

In vacating the judgment and remanding for a new trial we do not set aside the finding that defendants made and breached the implied warranty of fitness, however, for the same undisputed, unambiguous evidence referred to above also establishes as a matter of law that defendants made and breached that warranty. G.S. 25-2-315. For it is a matter of common knowledge that the motor in a new motor vehicle is of substantial importance to the value and utility of such a vehicle and the uncontroverted evidence shows that: The motor in the vehicle plaintiffs purchased was warranted as a new motor; barely a month after the purchase the motor failed to perform like a new motor and the seller and warranter after inspecting it had the motor taken out and replaced. Nor do we order a new trial on plaintiffs’ unfair and deceptive trade practices claim, not reached by the jury, because the evidence presented does not support that claim. The evidence presented, even when viewed in the most favorable light for the plaintiffs, as our law requires, only shows that in selling a motor vehicle with a motor that was defective and had to be replaced defendants breached an implied warranty of fitness, and that is not enough to establish an unfair and deceptive trade practice under G.S. 75-1, et seq. Warren v. Guttanit, Inc., 69 N.C. App. 103, 317 S.E. 2d 5 (1984). Since it has been judicially established by the evidence of the parties that defendants made and breached *527an implied warranty of fitness for a particular purpose, and that plaintiffs revoked their acceptance of the motor vehicle in a timely and effective fashion, the new trial will be only on issues concerning defendants’ allegation that plaintiffs withdrew their revocation of acceptance and on plaintiffs’ allegations that they are entitled to recover actual and incidental damages. In the trial of these issues statutes that should be consulted include G.S. 25-2-711(1), G.S. 25-2-714 and G.S. 25-2-715; and the decisions that should be consulted include Davis v. Colonial Mobile Homes, 28 N.C. App. 13, 220 S.E. 2d 802 (1975), disc. rev. denied, 289 N.C. 613, 223 S.E. 2d 391 (1976) and the cases therein cited.

We overrule plaintiffs’ several other contentions without discussion because they are not based upon exceptions properly taken and assignments of error properly made as sections (b) and (c) of Appellate Rule 10 require; and we overrule defendants’ cross appeal without discussion because the arguments made in support thereof are not based upon any assignments of error, as Rule 28(b)(5) of the appellate rules requires.

Vacated and remanded.

concurring in part and dissenting in part.

I agree with the majority opinion that the plaintiffs are entitled to a new trial. In my opinion, however, the next trial should embrace all issues raised by the pleadings and the evidence presented at the new trial. I do not agree with the majority’s efforts to restrict the new trial to the issue of whether plaintiffs withdrew the revocation of acceptance and to the issue of damages.