If you are getting the banned message, use the Log Out link at the bottom of the banned page, then clear your cache and cookies; that should remove the cached page and should allow you to log in.
If you think you may actually be banned, provide your handle so someone can look into it, but bans are generally reported on the Sim News (which can be read while logged out).
Okay when I do that is a screen telling me when it's done because it hasn't done it yet.
After about 5 minutes of waiting I tried logging in and I got the same thing telling me I was banned.
Just in case I was banned my handle was Barron Marsh.
Yes, that handle actually is banned; was banned by Alizee Anna Tia for reason "Accidental multi". You can contact him at multi-accounts@swcombine.com to discuss this.