Banned from talking

You can try submitting a case review at
http://enforcement.xbox.com However, it doesn't matter how the situation starts. If you respond in a way that violates the code of conduct, you can be subject to punishment,

All enforcement actions are handled by the enforcement team at their website. enforcement.xbox.com

They do not monitor these forums.

While on their website it will show you your enforcement history and if eligible you can file for a case review there and they would then reinvestigate the case and determine if they can lift the suspension sooner.

Keep this in mind Just because someone talked trash to you even if you talked trash back to them your just as wrong as they are and are subject to the enforcement actions

The best thing to do in a situation like that is to block the person and mute them and report them.

Hey Lego thanks for taking the time to bring this issue to us

We are sorry to hear about any issues you may be having due to an enforcement action.. Unfortunately as this is forum support, you will not be able to reach
the enforcement team here, and we wouldn't be able to assist further.

You're welcome to create a new account (which I do see you state to have made this one) and use it to play on Xbox as this is a new account with no enforcement action.

Also I would recommend to take a look at
Microsoft’s Code of Conduct Explained for Xbox Live Customers.

Please visit our
Code of Conducton
the enforcement site to find out how to stay safe.

We'll be locking the thread, as this has no further resolution.
If you ever require any help with any other issues please feel free to come back to the Xbox Forums for further assistance.

Are you talking about getting banned from the MP?

If you're only banned from NBA2K11 then it's a game specific ban which Microsoft doesn't handle. You'd have to talk to the developer.