Greetings from Russia! I have the same problem, and I haven't been able to do anything with it for a month or two. I have used 3 cards from different banks. Of course I have contacted Apple Support, but I haven't received anything that could solve my problem: just some generic things like clearing cache, etc. I don't know, why can't Apple just make an Apple Pay checkout for this payment? That would be convenient. But now I can't do anything but wait for a change in this situation and try to enroll again and again. I would really like to publish an app for my university that I had been working on for several moths. I really love a lot of Apple things, but this situation really frustrates me. And as I can see, many developers all over the world face the same problem. I hope something will change soon.