FNB abusing poor customers

An employee of mine has been endlessly abused by this bank. They have apparently opened an overdraft on his behalf. It is overdrawn . He knows nothing about it . Has been to the branch in Kokstad to ask why he has an overdrawn amount. Was told to phone the number on the demands he’s being sent. He doesn’t have that sort of air time. He came to me and we phoned the number to be told we through to the wrong department. So eventually we got a direct number for the underberg branch . Arrogant case by the name of precious said she could only help if he came into the branch. I suggested proof of the signed agreement be emailed to the employee , answer no can’t do that she busy with a client . He has changed to standard bank in desperation. Still getting threatening letters by registered mail. What is one supposed to do.