Most often a ban is a result of trying to get back onto a server after a PunkBuster kick. Normally the ban lasts till that map changes or after that round. Its an automatic thing, nothing personal. Have you tried to manually update PB and can you join 2142 servers? Sometimes a 10 min run around a 2142 server is enough for PB to update its self automatically

"Something something something Dark Side.. Something something something Complete!"