The trouble is, you can't prove how little you've used it, so you would just have to put on your best innocent face, and hope the retailer takes your word for it. It certainly might be worth speaking to the Manager of the retailer, who might do something for you to maintain good customer relations, otherwise, I would contact the manufacturers, Dave. As you say, you do expect an item to outlive the warranty by a little longer then three months, but you might have been more hopeful of some recourse, had you done something about this sooner.