*censored*.
OK, let me explain this.
the forum and the chat are completely separate. There is a chat section on the forum but A:) if you were k-lined, g-lined, or otherwise banned by mibbit nobody, not even The admin here, can't "unban" you. He simply has and manages a channel on mibbit, that's it. It seems all to common that there is some confusion over exactly what the computerhope chat is- many feel that it is a "part of the site".
Of course, if you were banned at the channel level by Hopebot or another Op, you should PM The Computer Hope Admin (or discuss it here when he drops in, assuming you are able to enunciate more then a few words of lol speak combined with swear words- which may be the reason you were banned from chat).