Backstabbers

So the other day I showed my friend a server that I really liked, and so he invites all his other friends on also.
So I got off mc and, later that day I went to get on the server. Well guess what, I was banned for griefing! So I checked skype and my friend told me they were griefing the town. Well I got skyped by my other friend thats on the server and he's telling me that the owner found me griefing. Turns out they got a mod that lets them turn into any player in minecraft, and turned into me. My friend that backstabbed me was a huge idiot for leaving me in the skype chat with them and I now have proof. Well the owner didn't wanna hear that I have proof, so now I'm stuck banned ;(