I loaded a gift card for $88 (my total in the shop) and tried to process the card. It just sat and sat with "transaction processing, please wait" for fifteen minutes. So, I tried to use my regular credit card and got, "Your card does not support this type of purchase". Upon investigation, it seems that I got that message because it's a debit card.
So what! Why can't they run a debit card as credit like **every other card processor on the planet**? I had to use a third credit card.
This entire process was stressful due to the limited nature of the things I was trying to buy.
Hopefully this helps anybody else who has the same problem.