It's been going on for 8 days now. Trial account is going to run out soon and I do actually enjoy playing the game, but if I can't buy a real account then I'm going elsewhere.
I'm trying to buy via paypal. I login to my account, got to the store, click which version I want to buy (architect, in this case) and then it starts to check me out, I click confirm from the paypal page, and then I get the message.
Thinking it might be a paypal issue, I also tried with a credit card. Same results.
My wife had this same issue a couple times when purchasing upgrades, and I'd like to join her in the game, but if they don't sort this out soon, I'm going to talk her into playing WoW or something else with me instead.