RAIN SOUTH AFRICA REFUSE TO REFUND A DOUBLE DEBIT

I have a bad experience with Rain South Africa. I paid my sisters account on the 30 Sept 2024, something I have always been doing for over a year. On the 1st Oct 2024 they have debited me and we contacted them to refund me because I did not budget for double payment. Seemingly they cannot refund me. I now need that money and I need to close that account because of how they took money from my account without my permission.