Bad service

On the 14 of may 2022 I transferred money to my sister account because I didn't have my card with me. And I needed to buy something but couldn't since I wasn't near any Capitec ATM neither ShopRite ,picknpay, pep, boxer or any retail store so I couldn't send myself any cashsent hence I transferred to her account. Disadvantage her limit was R20 therefore I couldn't use the money, ending up not buying that certain thing I wanted to buy. Have been begging her to transfer me back the money that I had given her but she doesn't want. So I personally went to protea glen Capitec to ask that they have her account frozen until she agrees to send my money . They told me the is absolutely nothing they can help me with!!! Which kind puzzled me that the whole bank cannot do that. I have a prove of transfer and everything so what if I mistakenly transfer someone so money which means I cannot get my money if that was the case? Because I didn't ask them to reverse it but freeze the account until she agrees to give back what is mine . Hope I would get help since this is my last option My account number is *** and her account number is ***