No feedback after incorrectly being handed over

I have been in dispute with mtn for months. I was told the matter is resolved however mtn has not updated my credit report. I called mtn legal on Thursday to get a formal response on a letterhead to say I don't owe mtn and was supposed to get response on Monday but nothing. Now I call again and I can only continue with valid contract number which I dont have cos this contract expired years ago. This issue is causing problems for home loan applications and I was not even at fault. I need someone to contact me and not just respond online or via automated response.