If I remember correctly there are several type of bans at CB. By default if you are banned by kicking your ban lasts for 6 hours. Not sure can performer ban you permanently or for some period of time. What I am sure, you can google for "chaturbate ban" and among the first google hits you will find the explanation.
Considering bypassing of the ban you can do it simply by going into same room without logging into your account using different browser only. If you don't want to use another browser you can use anonymous proxy server (also without logging into your account).
As far as I know you can not enter into model room using your banned username as long as you are at her banned members list.
However, if you want to be a bit bad you can create account with similar name and log in into room again but be sure you will be banned as soon as model realize who stands behind it.
Good luck
