My iPhone (5s) has randomly started to ask for verification (before you can make purchases, you must tap continue to verify). Now my problem is that with my apple account I already have a bank account linked to it which I have used on several occasions. Now it's saying my payment method has been declined, and the problem isn't with my bank account because I have tried to put in 3 other bank cards all of which been declined for no reason.
Has anyone encountered this sort of problem before. If so, do you know how to fix it? Additionally I can't remove any payment methods because in my settings there's no 'None' option to select if i don't want a payment method.