Failure by the bank to resolve and resolve the dispute

My father who is 83 years old and has been banking with ABSA Bank for approximately 35 years.. Money was withdrawn in February from his bank account and there wasn't any notification with this incident. The second withdrawal was withdrawn in August and an amount of R4000. The challenge is that a total of R12000 was taken from his personal account. The bank has been informed about this issue and said that they can't assist us with this incident and we have had to move his bank account to another bank. I am shocked that a man who has been loyal to the bank for so many years and cannot be helped with this incident. He has suffered so much bank charges for the current month. Is this the thank you that he receives in his old age years