I can't believe I'm having to type this...
I have been attempting to get Cafepress to send the prize for two weeks now. It has so far not done so because (get this) it won't accept my credit card!
As far as I can tell there is nothing wrong with the card itself or the account to which it is attached. Going through Cafepress's help system has been useless - after giving me some elementary tips I'd already tried before contacting them, they simply sent me to an American phone number (even though my shop is registered with the British arm of the service).
I may have to rethink how I deliver the prize; it may even end up being a straight Paypal transfer. But I am really frustrated with Cafepress and thought I'd better tell you what's happened