I recently booked a cruise with Cruise.com on Carnival for Christmas. They were running a promotion of up to $500 on-board credit depending on the room price. After spending an hour on the phone booking the cruise, the operator stated that we did not qualify for the credit since we didn't use a mastercard to pay for the cruise. They had already rung the transaction through on another credit card. After booking the cruise I went back to their website. There is nothing on the website that says anything about needing a mastercard. I called... read full review »