Bad customer service

I took a phone contract back in 2021. Towards the end and the beginning of 2022 I had financial issues which led for my account to be handed over to their debt collectors. When I managed to have my finances in order I called MTN and I was advised that the matter was handed over. I called the debt collectors, requested for the balance. They told me the balance, that’s was not a true reflection which I mentioned that on April I paid R7000. Called MTN to raise concerns about the matter, to have the account updated so I can have a true reflection of how much I owe and make a rearrangement with the debt collectors. I was still not assisted. Decided to go ahead and make payments. First payment never reflected. I called and enquired about the issue to the debt collectors. I was advised to send proof of payment via WhatsApp which I did and nothing happened. I was skeptical with the matter and decided to save the money and just make one payment to close the account. Reached out to MTN never gotten assistance, did follow ups for more than 8 months requesting for the outstanding balance that I owe so I can settle the account. I still haven’t received assistance till this day, with continuous follow ups but I still don’t receive feedback. What’s strange they keep sending me statements that belongs to someone else and that’s against the POPI act which I did bring to their attention but still, I keep getting those statements. This has a huge impact on my credit record because by now my credit score would have been in a better position