I don't understand why this is happening to me either. I'm in Australia, my card and financial institution is Australian and it says that in my profile. If SE has locked me out of my account for a month because of their own system incompetency I'm not going to be happy.

The only reason I can think of is because I'm connecting to a JP server since they have the lowest latency and there are no Oceanic servers. Either way, I'd have thought this'd be a pretty serious issue that would have been ironed out early. Must be difficult if it won't die.