Can someone help me please?

So, about 4 months ago, like all you guys, I purchased all the dlc including Roy, Lucas Ryu, etc. And ever since my birthday, I cannot access my receipts for the dlc in order to get them unlocked in the wii U version. Obviously, it gave me an error code, and all it said was to restart my system, and that of course didn't work. I've been trying access nearly every day, but it still doesn't work, so can someone tell me what to do?