I recently did some research into consumer law. The distance selling regulations have been replaced in law by the new Customer Contract Rights. These do give the seller some protection against returns on frivolous grounds. However you can still just change your mind within the 14 day period. The seller should have sent their T&C's regarding the contract outlining the legal position for returns/cancellations. But even then your rights should trump theirs if you have quickly cancelled. If they did not send any via post or e mail then they don't have a leg to stand on.

On the basis that they have suffered no loss or damage due to the change of mind then your deposit should be returned in full. If they state they have suffered loss or damage then ask for written proof of this on official documentation. i.e order forms, letters from their suppliers etc. I find it hard to believe that an order for a vehicle cannot be cancelled within a few days and would not expect any claims for loss on that basis.

Insist upon your rights. Cheers Concrete