[SmG Nukem]

Ok the way I see this is you and a friend share the same cd key. Obviously one of you is doing something wrong and getting banned or you have a common downloaded cd key that is banned.
You need to give us your exact in game tags and your friends in game tags. All of them, not just the one.
If either of you are banned for a reason the ban will remain. If you are using a downloaded cd key, you will need to find one that is not banned.
Just a hint, don't use any special characters in your game tag, it just makes it harder to find you in the logs to unban you.