You've had plenty of times to prove your maturity, all of which have failed. You are not in the unit, so you should not have been wearing any tags in the first place. You are responsible for anything that happens on your account, if you are going to let another person borrow it then you put your reputation in the hands of others. It's unfortunate that your brother decided to break our server rules, because this looks to be the last strike for you.
1st: Purposely TKing and Team Wounding in our servers
2nd: Enlisting with bogus information and without maturity
3rd: Allowing your brother to impersonate the 1st MRB on your account
It also sounds like you are a constant problem in the server, so I'm going to say that's it for me. Most players don't get as many chances as you did.
I would like to hear both sides of the story so that I can get a grasp on the entire situation. However, until then, Ban Stays.