My Frozen Account

I have my account that has been frozen by FNB early this year for something i absolutely didn't do a client paid me money for a service that i rendered then FNB blocked my account saying that the client used ********** money to pay me they asked me to do affidavit which i did and i even went to the Fnb Woodlands branch in Pretoria the branch manager even spoke to a lady by the name of Beverly in the forensic department to defend me as i have been a very good client with good records on my statements and that lady just said that i will never bank again with FNB meanwhile im completely innocent can you please hellopeter help me.