Where's Standard Bank's logic?

My mother's fixed deposit matured 2 years ago. The account that the funds were supposed to be deposited into was closed. My mother never received any communication to ask which other account she would like to deposit the funds. On 21 Oct, I went with my mother to the bank and got a Service Request number. On 23 Oct, an SMS said that the Service Request number was resolved and that she'll get a call. We waited, but no call came, so I sent an email on 25 Oct(by the way, I do have signing powers). On 27 Oct, someone phoned. My sister answered the phone, then gave it to my mother, but because my mother can't hear so well, my sister suggested to the consultant that she talk to him while my mother stands by her. He said it can't be done, then sent an email to say that authentication could not be done and therefore request cannot be done. Then we tried Facebook messenger. We told the consultant to please put the funds into one of my mother's savings accounts. No luck. They say they need to do authentication to prevent *****. I mean really, exactly where is the ***** if Mr Z puts his own matured fixed deposit into Mr Z's own account? If it was Mr Y trying to put Mr Z's money into Mr Y's account, that's a different matter, but not Mr Z's money to Mr Z's account. Anyway, we also tried the chat on Standard Bank's app. No luck there either. One would think the app would be secure enough to not require authentication. I really wonder at the logic of Standard Bank.