Cash back dispute not yet refunded

Good Evening, I would like to lodge a complaint on behalf of my grand mother. A cash back was requested on 03/09/2022 however after money was debited from her bank account the cashier told her that they are experiencing network problems and told her to come the following day with her bank statement and ID. That was done however the funds are not yet refunded, this has caused us alot of inconvenience as travelling to the store costs alot. The amount debited was R596. May this please be attended ASAP. This happed at Ejozni branch in KZN