On AfterNET, channels are mostly sovern, under the control of that channels owner. We (the AfterNET Administrators) have very little jurisdiction to interfere with the decision by a channel owner or his/her delegates to ban you.
The best we can offer is to help you with creating your own channel, which you can run better than the one you are banned from.
Exception: If the channel is #afternet, or #help, those channels are run by network administrators, and we may be able to help.