I am Getting the same error as you guys. Ive been able to buy gems on 14th of april but yesterday when i tried i got the error again.On the 14th April ive submitted a ticket and after 3-4 hours it worked .. the responce was :I'm sorry to hear that you were having trouble purchasing gems. I see that you were able to make successful gem purchases since contacting us so it appears that your purchase issue has actually been resolved.But the issue continue; but not only for me , many people have this problem.I dont have an issue with bank or anything ... i am purely unable to buy gems because GW2 doesnt accept my money.Also Question: Is there a limit of how many transaction we are limited in 24 hours ?Cheers.
I did , before i posted here.