I have the same problem. I tried with 3 different cards so far. All orders got canceled on the next day. I used 2 of the 3 cards in the appstore without any issues. And also use them for apple pay on a daily basis. The support trying to convince me that the problem is with my bank, but I am pretty sure that the problem is from their end. I don't know how are the things in the US with the online payments, but in Europe you have to provide CVV along with the card number. It looks that someone forgot to put a field for the CVV in the form. I guess they use a different payment processor from that in appstore, because CVV is required there.