Inconsistent balance

So MTN sent my owing balance to Experian which is just a little over R3000 and I wanted to settle with them, and I paid over R7000. It seems as though MTN didn't have my payment record because they had to "calculate". In their calculation, they didn't even have my latest installment updated, so he gave me an incorrect amount at first and I had yo confirm that I had payed my latest installment. I am not confident at all. What MTN has done to me is something I will never forget, the trauma and impact they had to my credit score is inhumane! Because of them, I hate the colour yellow! There's just so much I can say about their poor service, I am shocked that such a huge company handles customers like this and their process is the poorest I have ever seen, the most outdated ever! I want clarity on why it said I owe just over R3000 and I had to pay over R7000???? Where do you get these figures. I want a statement sent to me soonest. I can never begin to express how hurt and traumatized I am by MTN. I feel so helpless 🥺💔.