Poor customer service

On the 7th of January 2023, I made a transaction at Shoprite that includes cashback. I made two transactions but the cashier say it didn't when through. Request a statement from FnB and it shows that funds where release. Shoprite also showed me their statements and they didn't receive funds as well. I then when to FNB Jubilee mall branch for assistance I was told that they no longer assist walk in customer I need to call, I call dispute department they also didn't assist me to reverse the funds back in to my account. I was told to email all documents to complaint department. CAN I BE ASSISTED PLEASE. Total amount to be reversed back to R4700.00