Anyone else not able to charge NX?

you putting O's or zero's in, bcuz alot of people get confused and put O's when they are auctally zero's.
I have a problem charging nx to now using card codes, idk if its my interner browser(firefox) or something else, and since I work most days and dont really get nx anymore unless I get it in game it doesnt really matter.

I'm not confusing anything. I substituted all the 0's in the code to O's and nothing happened still. It said invalid card, but I know the one I'm trying to put in is correct because it says system error.