Early settlement amount

I have been struggling to get any sort of feedback from MTN, I want to terminate my one number with them, but no one seems to take me seriously. This has been going on since end Feb, I received figures from Nonkululeko Makahathini at retentions, but it was an estimated amount and if you look at the email, it also did not look correct. Since then I have tried all avenues, even the MTN branches that I have been to have been very helpful, but also don't get any response. I have also involved the local area manager in the East London area, but it seems that even she are unable to come right. I find this unacceptable, I have been with MTN for many years and will still have two other contracts with them, this should be straight forward, it should not take weeks to figure this out. I urge them to pls make a plan to assist me, the following reference numbers was given to me: ***4 and ***, all I am asking for is a letter stating the amount that I need to pay in order to settle my account.