SSD is a ****

This company is abusing me big time.I had an accounts with Old mutual which was handed over to this SSD/ Shapiro Shaik Defries.I communicated with them on the 31st of August they gave me the the settlement amount of R1797.I sent the money to them and forwarded the proof of payment.They phoned me same day the lady by the name of Disiree Peters contacted me and told me that the amount mentioned above was not approved by Old Mutual as it was discounted as settlement amount.She told me I must pay R967 to settle as full amount. I paid same time and sent both POP.She confirmed to have received the proof of payments both.I asked for settlement letter. She promised to send after few days.Few days later She sent me a statement with a balance of R1050.I requested her to rectify as I have settled as per our communication.Since beginning of September 2023 they are calling me now saying I owe R2400.I have sent all proof of payments and explained to them that I settled.All their consultants are promising to solve the issue.I went to enquir with Old mutual as at one stage they said old mutual is the one that is not solving the issue.Old Mutual is saying on their side I do not owe them nothing.I informed them but still fails to solve the issue.I do not know what to do now.