I am not the expert on payment issues but could it be that you've changed locations recently? I noticed that you have Nicaragua set as your location here on the forums..
edit: if it's not the location, then please send a ticket to Support :)
Yeah, I did change the location, and it will probably be Guatemala next week. But that's the usual business for me, and I already bought Rune from Nicaragua a few days ago.
I'll contact them if it persists for a while.
EDIT: Just retried and it went through, so that's that.