i meet it few time , bann in website faster than in game few hours . try to run your gold , item , guild . . . . . . . .
This happens when your billing is pending. Check your billing status. It is probably just still confirming the billing.
Yes this is an annoying problem internal to wow billing. They don't fix it quickly either. You are kinda SOL on the mobile app side till they do whatever they need to. The 1 year commitment offer had something to do with it as well. Earlier this month it was all over the blizzard forums. Many had signed on for a year last year and we're affected.