Help! Swap Force (Wii U) won't load past initial splash screen! ?

So I ordered Swap Force for the Wii U off of eBay. Very trusted seller. But it just won't load past the initial splash screen! It either just does nothing and keeps playing the music, or it goes black and still doesn't load. I tried resetting the Wii U, nothing. I also tried disconnecting and reconnecting the portal. I ejected the disc and reinserted it. Nothing even seems to be wrong with the disc. It's perfect. Not a single speck of dust. My only idea is to delete the old data of the game still left on the Wii U, it could be interfering. I waited patiently for this to arrive, and I need help on what to do! I don't want to just have to find a different game! tl;dr Swap Force isn't working, and I don't know why. Help.