Current: if there is a payment problem e.g. I changed my credit card number, then OneDrive just silently cancels my account, and my OneDrive shows up as full. I wasted an hour deleting excess files until I noticed that 'full' happened because I suddenly dropped to 5GB.
Requested: A UX notification that the problem is actually my payment card. Nearly everyone will roll their credit cards every few years, so this is going to happen to a LOT of users.