I got banned for no reason...

I literally have never done any type of boosting, modding, or anything for this game. I went into a search and destroy public match, got 3 kills, and a defuse. My screen then turn completely black and sent me to the main menu and this pops up: http://i530.photobucket.com/albums/d...01217-1749.jpg

I would love to know why I got banned because I never did anything wrong. My gamertag is Kraxin HiT and my aim is jsb62891 if you would like to get in touch with me.

Thanks.