Same here!. But when I contact my bank and ask them about my problem. They check my card and said it work normally and they said maybe it because I try to buy so many product close together in time and max of qouta. And all of the list of DLC that I buy before I got this problem still waiting for Origin to contact my bank for real charge!. So maybe I need to wait until all of the list (or some) of them got the real charge from the bank and then The Origin may accept my card again I think.
Then may I ask something? How many of DLC that you purchased before you got this error ? or it's the first DLC that you purchased in around day (or week)?. For me I try to purchased all of dead space 3 DLC until I purchased Enervator and that when I got NU2001 Error sh*t!. It's Enervator and EG-900SMG only two DLC that left WTF!
And sorry for my bad english any way . haha T.T