Dumb cartilage piercing?

So about two months ago I made the wise decision to get my cartilage pierced at Walmart. That was fine and dandy. Well, I want to take the earring out and replace it with a hoop. I cannot get the earring back off. I guess they invested in new backs? It's a bell back, but it is like locked on. The woman that pierced it told me to put the back in, then pull or something. I don't quite remember. I just CANNOT get it off. Any suggestions?