Billing info problem

So I’m trying to download an app that I used to have which is free, but when I try to download it it says this:

First of all there’s no “continue” button to press and second of all its free so why do I need to go over billing information?!

Then I went into my billing information, with everything typed correctly (I use the exact layout when buying online, so it’s 100% correct) and then this comes up!

Quite confused on what’s going on because I’ve never had this problem before.. It’s a pain because I need to download apps like google docs, google classroom etc (for school) but I can’t because of this error.

If someone could help it would mean a lot 😇

(iPhone 6 - 64gb)