HORRIFIC SERVICE!!!!!!!

I have requested a settlement letter from Nedbank to pay my credit card, which is on debt review. I have made the payment 11 days ago. After following up 3 days later having not received any response, the agents told me to send proof of payment. which I have done 8 days ago. I have then once again contacted Nedbank to find out if the payment was allocated 3 days ago. The agent told me that the payment has still not been allocated and that I need to wait another 3 days. I have contacted the debt review call centre again today and the payment is still not allocated. The agent told me that I used the wrong reference number for payment. I asked the agent to have a look at the proof of payment as well as the settlement letter which was sent to me by Nedbank and asked her to look at the reference number that Nedbank told me to use, which is what I did. After which she dropped the call. I have phoned the call centre 5 times, sent two emails and waited 11 days and my querry is still not sorted and no one can help me as they work from home and can't put me through to a manager. This is terrible service, and I will never recommend Nedbank to anyone ever again!!!! POOR POOR POOR service!!!!!