I had the same problem and circumvented it while on the phone with support. I had to complete the process through my mobile rather than on my laptop. I would get to a point where it would quickly open up a pop-up page with a confirmation page for my bank and a confirmation code to enter, but the site would never give me enough time to be able to enter in the code before kicking me saying that it couldn't process my card information. This was VERY frustrating. So when I did it on my mobile (Chrome) I was able to keep that pop-up page open somehow and enter in the confirmation code to run the process of my payment. I think Apple might have to fix something in how long it provides customers with time to enter information in that pop-up window. This is assuming you are running into this particular same issue. I hope this helps.