I have a pretty thick "Citadel" chain that I use to lock up my bike. Saturday night, I went to the train station to retrieve my bike and I could not unlock it at all. I think someone messed with the lock, trying to get it open. Does anyone know how I can get my bike free? I'm going to go to a bike shop and see if they can help me. If they can't, then I think I will try a locksmith or try to get my hands on a tool to cut the chain, but either way it will probably be expensive. What do you suggest?