Bad service

December 2019 we realised that the was money missing in my mother's capitec account, whom is a pensioner. An amount of R3100.00 was transfered from her account to someone we don't know. We went to the bank to lay a complain. They open a case and told us they will come back to us in the next 7 working day. We waited for 4 months. We went again to the bank branch, they told us that the money can't be replaced,because the the money was transfered and it means my mother gave the pin to the people who stole the money. We even went as far is opening a case at SAPS. They told the police the same thing. Im not happy with their service, how could people go through other people's bank account and the bank the take the blame for that?