I too received the dreaded email today. I told them I have updated my billing address and credit card info and I can use the card for everything, EXCEPT SE OF COURSE. I just want to pay for the game. After reading the whole game time card thing and all the issues caused there, it seems that they just make billing such a hassle nowadays.
I want to buy Crysta and I get an error. I want to use a credit card, and I get an error. I want to pay for the game I love, but it's a little hard to do that when they blame billing errors on your bank card. I've tried 4/6 cards and they all get the same error, and I use them just fine everywhere else, so at this point I am absolutely clueless as to how to pay for my account. I am hoping come Sept 14th my account isn't shut off, because then I will really be pissed. We're military stationed overseas, and SE doesn't support APO addresses (because nobody in the military EVER plays video games.. /sarcasm) so it makes no sense. It's really, REALLY getting frustrating though.
Also I've tried using a VPN service and having someone from the US (in the physical billing location) use my card as well - nothing. I've tried Visa and MC. For them to continually say it's a problem with my card is balls, because I JUST PAID FOR SOMETHING without issue. Without one small tiny issue. It's NOT my financial institution - it's clearly something on their side...