Swiss Tony, you got the wrong answer. Hilton is an international corporation, if ever there was one, and they've been around for a long time. You simply are not the first Briton (or Swiss Briton ) to whom they are writing a cheque.

I think that, rather than going through all the gyrations of opening an account in the US, or paypal etc., for a one-off, your straightest shot is to keep on the phone with Hilton. I believe you got someone who was at a loss (benefit of the doubt). Either keep calling until you get someone who can make it work, or work your way up the chain. I believe there's an advantage to the cheque, because you can make a stay and a double dip of it.

EDIT: But I do think it would be fun, first, to try using the one they sent you at a Hilton in the UK..... [Insert grinning smiley here (not possible on edit).]