Ver bad service

My dad went to ABSA to cancel his Bond. It has been paid off. Then on 21 Sept 2021 he got a letter from Nasima Khan's office to tell him there is an amount of about R 5268.50 outstanding to close the account/bond. When he received the calculations, it was actually about R 4618. So from the start giving him wrong amounts. He paid this amount on 30/09/2021 Now suddenly on 20/01/2022 he gets another account of R9038.50 for cancellation of additional bonds??? What bonds?? He only had one bond?? This is crazy, looks like someone is taking a huge chance. And it has been more than three months now. This is the worst service I have ever seen.