Thank you for your help, the address was the issue. I had the same issue: https://developer.apple.com/forums/thread/749129?page=1#787630022

Solution here: https://developer.apple.com/forums/thread/129331?login=true

What a helpful place this is. Anyway, the issue seemed to be my address as it didn't like Flat A, preferring actual premises (imagine demanding that from "generation-rent"). There was no issue with my Debit Card payment.

Bem feito.