Shoutbox

If you only use your email for xbox, it's likely you got banned for being reported a lot of times by other players.

And yes, you can be unbanned, they have the power to ban and unban you. Usually if you get banned for something you did on XBL it's only for 24 hours for a first time offence.

It'd be easier to help if you told us where you got the message telling you you were banned, what exactly it said you were banned from and furthermore what the message said in its entirety.