I tried adding a prepaid debit card to my payment options, but after entering all of the info, i was taken back to the add credit card page and a message under the credit card space says "Please enter a valid credit card number." The card is valid, and active. I retried several times, on both xbox.com and the console, getting the same results. Eventually i said hell with it and decided to add my actual debit card, you know, the one the bank sent me. "Please enter a valid credit card number." Neither card is going through. Not here, not on the console. Is this some kind of sick joke? What am i doing wrong?