LACK OF INTEREST AT ABSA

my experience with absa Malvern when I went on Friday 09.10.2020 with my mum who is 84 years old. I had picked up that my mum account has been debited for various amounts from March 2020 till present . I had went to the branch and I was advised that these transitions cannot be reversed and that they can give her a new card which they did. After coming home I given this a lot of thought and realized there was no concerned to my problem and I want this money re im bursed. She was given a new card, I want an investigation into this matter . As to how someone has access to the bank card and how someone was able to use her CARD whilst it was either on of us .This is totally not acceptable after all my mum is a pensioner .