How come I got banned?

I came back after the weekend and I couldn't log on. It came up the 'Ban Hammer has spoken!'

I haven't done anything wrong and I have a house in Beachtown which I spent ages making.

Can someone tell me what's going on?

My account name was Xenon and you can ask Minecraft1127, Juju, maybe SlayR or westy that I had never done anything wrong.
I'm really sad that I got banned (if I did) because I was really enjoying myself on that server.

Please help me