The payment option was a non refundable rate, so I could use one of those extra night's credit vouchers. So I paid hotels.com online at the time of the booking. The bookings show up in Euros exactly as booked on my statement. I really did get a credit card receipt from reception, can't remember if it was directly for my card (because I don't have the receipts here at the moment) but I imagine so because I had to show my card at check in presumably as a guarantee. A bit mysterious in a way, but I was charged exactly what I booked and I was happy with the price, as well as the hotel itself.