Accounts are autobanned because of Plagiarism (copy/past others contents) or because of posting useless posts (spam). If you see a time limit in the text shown on your session then it's a permaban and you just have to wait a few time. If not, then forget about posting or sending PMs with your account.
Note: banned users are not allowed to create multiple accounts. So just use this account to discuss your situation here.

Check this: https://bitcointalk.org/index.php?topic=5043370.msg46482193#msg46482193