Cell C

I am writing on behalf of my mother. Cell C owes my mother, 82 y old, around R4000. (According to her). It is difficult for her to communicate. She did not sign a debit order with ABSA. She used to do an EFT to pay CELL C. For the past few months Cell C managed to take money from her ABSA account without her consent. I would like to know where this comes from and how is it allowed? I did not check for deductions before 15 Nov 2023. On 15 Nov 2023, CELL C took R1794.43 from her cheque account at ABSA. On 14 Dec 2023, Cell C took R1867.43 from her Absa account. On 3 Feb 2024 Cell C took R1867.37 again. I checked myself on her ABSA banking app. There is no debit order or debicheck on her app for Cell C.