Money Market Cash Vanished

My mom deposited money at OK Grocer Doornpoort on the 12 December 2023 between 07:00 - 08:00. 15 December 2023 the person she tried to send the money to phoned her to say she didn’t receive the money. My mom stays at Kwaggafontein and works in Pretoria, so she is not always able to go back to the store whenever she wants to as she doesn’t work every day. My mom was doing a bit of shopping on the 12 December 2023, so she had many slips with her resulting in her losing the slip from OK Grocer. She went back to OK Grocer on the 19 December and Sonia checked her system and gave her the M number of which when she tried to retrieve the money then she got an error message stating the M number is not valid. She went back on the 8 and 9 January 2024 and she was told no one can assist her as she has lost her slip. I made phoned OK Grocer several times on the 9 January 2023 and spoke to Lizelle and Oom Herman of which I was told by Oom Herman that there is nothing he can do to help us. I do not believe that R1900.00 can just vanish and OK has no record of this even when searched with her ID number. I phoned Shoprite head office, and I was told that I need to speak to CPT ***. I phoned CPT and they transferred me back to JNB Ok head office. I have been taken from Pillar to post since 8am this morning and still going nowhere an hour later. Can someone please assist me as I do not believe a supermarket can lose record over a period of less than a month.