Absolute shocking Customer Service

I made a incorrect payment with Zapper and immediately reported to FNB. Let me also say there were not enough funds in my account for that high amount but FNB approved it. I completed transaction dispute forms and sent through. 2 days later I got a message to say it was resolved and my account balance adjusted. This was on the 15th July and to this day I am still waiting. I have had many secure chats on the APP and have been told different stories every time. The I called last week Thursday to try get it resolved and once again all that could be done is to escalate it. But was told Amanda (who was dealing with the case) would call me back. It is 6 days later and still no phone call. I did however get an email requesting more documentation last Thursday ( this is a week after it was apparently resolved) which was sent through on Friday,26th. No response. On Monday I sent a follow up email requesting acknowledgement and a response. I received a "read Receipt" but still no word from the agent. Just called again and was told it would be escalated again. What the heck is going on ????? This is the absolute worst service ever and I have no idea what to do next.