Bank not doing Fica correctly and holding client to ransom

I have been banking with FNB on the business account for over 4 years. i opened the account with current shareholders with no change to my share holding, the address or any trade changes. The bank sent me some Fica form last week that i have to fill out. i asked them why, the agent then said that they had made a mistake and that it was escalated to another team as it look like a false trigger in there system. I went over seas on business for a week and found out that FNB has frozen my account. they now say they cant find on record my previous call and will not look for the voice recording. the document they want me to sign requires all directors of which some are away. they refuse to help. they cant say why it was not there before or how i got my account trading for all this time and they don't have the document.