Hi, I am having exactly the same problem in Australia.
Have tried multiple Amex and Visa. The Amex cards are already used for Apple transactions very month.
Address used is same as credit card billing.
There are 4 HTML errors on the page in particular loading the marker to indicate where the error is on the page. The page is strange in that it does not support Safari's autofill for credit card details.
If I force errors then an error is shown quite quickly. This error takes longer and you get the message at the top but no marker against any fields to show what is at fault.
My billing address has a "-" in it which can cause problems with some badly written address checkers, no way around that as that is what Amex and Visa have on file as it is the official name for the suburb.
I would be surprised if Apple is doing a check of $0, in the past to verify cards I have applied a credit of 1c as this rounds to 0 or stays at 1c and has no transaction fee whereas a 0 or positive amount has a transaction fee which is more expensive than 1c.
I have raised the issue 4 times, 4th time I received a response advising that it had been escalated for resolution.