App Store

I've been trying to download free apps off the app store but it keeps telling me verification is required. I removed my current card and currently have no card on file so there's no billing problem. Even when I try to put my current card in again it says that it won't accept it even though it has been on the account before and worked fine a few hours ago.

Basically, it won't let me download apps when the card was on and now it won't let me download apps with no card on file. Nor will it let me put it back on file.