This is just an automated message so don't take it personally. Just contact the Admins and your registration should get resolved.
Amibay has had issues with banned members setting up alias accounts, spammers and hackers attacking the site. Unfortunately, their automated system can't always tell the difference between legitimate and illegitimate new user accounts.
If part of your registration was missed or your IP doesn't resolve to your location then the security system kicks in and auto bans you.
Drop an email to the admin address and they'll sort it out.
