Capitec refusing to reverse my mother inlaw's money

My mother inlaw who's a new capitec client and a pensioner transferred me money using to my other number that's not linked to my capitec account. I then told her to go reverse the money coz i can't access it thou I've been using this number for almost 3 years. She went to the bank to reverse the money but they failed assist her. They are saying she needs to contact a lawyer. Where can a pensioner afford a lawyer? I was called by capitec head office, I told them I'm using the money and I've never received any money on that number except the R800 that my mother in law transferred. Then money is still her on the account but Capitec doesn't want to reverse it. It's so unfair, R800 is alot of money to q pensioner. And that money i was supposed to buy her something at dischem on their black friday special.