Originally Posted by
Shareholder
What's not to understand? OP paid with MasterCard but the hotel uses the word "Visa" as a universal descriptor for all credit cards (rather stupid of the hotel's accounting system). Since one must send a copy of the check-out folio showing the use of a Mastercard to pay for the stay to be eligible for the $50 Mastercard gift card in this promotion, OP is concerned it will be invalidated by showing "Visa" instead of "Mastercard".
I see, wasn't familiar with that promotion and read the question from the wrong angle.