Theft with debit order

I am writing on behalf of my sister, Feima Rapolai, who clientele has been debiting her for almost 6 months, and when she calls them, they are unable to explain what the money is for, as she has never signed or had an agreement with them on any product. She approached Capitec, and they gave her clientele numbers to call, and even on Monday they continued and deducted again. Please help my sister Peter; we want the clientele to refund her every cent. The total amount deducted already is about R850. My sister No: 073