Best Buy Service Plan?

My iPod mini's battery won't hold a charge and I bought a service plan at Best Buy. It also freezes and ons won't work sometimes. I brought it in and they sent it out. When I got it back it as worse! Both panels were pried off with a screwdriver or something and the metal of the shell is a bent, so I brought it back to Best buy and when I got it back it was exactly the same! Should I bring it back again or do I have any other options? The battery also still doesn't hold a charge.