FNB unable to allocate funds back into my account after being refunded by a supplier (Makro) - the agent can see the refund confirmed that FNB needs to allocate to my account but no one is assisting.

I bought an item online for Black Friday special, the merchant then responded two days later that the item is out of stock , they processed the refund and sent me a proof of the refund, FNB received the funds but is failing to allocate the funds back to my account, I have called numerous times, FNB agents keep transferring me from one department to the next and eventually cut-off the call. I tried using the secure chat on the App , after been transferred to a number of consultants, I was referred to an email dispute department, sent email still no response from FNB and my money is still not cleared back into my account. What a horrible service