I got an tool from my bike store for pushing the rivet out of a chain. I tried it out on an old bike to get the hang of removing a chain. After successfully removing the chain and reinstalling, I tried to remove the chain from my bike in order to clean it. After coming into contact with the rivet, I can't turn the tool any more. It just won't move no matter how much force I apply to it. The bad part is that the link that I was working on is really stiff. What now? Help a n00b out.