MTN NO SETTLEMENT LETTER /FINAL ACCOUNT NO CREDIBLE DETAILS

I had a contract with MTN which i decided to close early when i got retrenched. I contacted MTN they said my account is with their legal department . P.S you cant call the legal they put you through. I was given an email and emailed . I was told to settle and close my account i needed to pay R7000 outstanding. I paid this in 2016 . 2years later i am told MTN has me listed for oustanding R2880 . I email the same email address the lady responds it turns out she says i owe R9380 i respond and say how about the money i paid etc . A didd person responds saying they never recieved it or allocated it turns out they gave me a wrong reference in 2016. The lady emails - Tshepiso Moletsane saying infact i owe R13600 I email back saying why has the amount changed. PLEASE CAN THEY SEND ME A STATEMENT OF THE CALCULATIONS AS WELL AS THE SETTLEMENT LETTER THAT I CAN USE TO REMOVE THE LISTING ONCE I PAY. She sends me a statement on a word document and the amount goes upto 2016 no interest nothing. Another lady - Kamohelo Mosia responds saying less the R7000 i paid i would owe R9860 instead . This is in a space of 10 days 4 total amounts for an account i was told i had settled 2016. Is it legal that they can not give me a settlement letter on a letterhead with the calculations and the total valid 7 days so i can settle officially. It sounds really backdoor that they cant generate this correct details plus reference plus MTN letterhead . If in 10 days i have 4 amounts i will pay this and find myself back in the same place 2 years later listed for another amount. I cant use emails as proof of settlement they are unreliable that is clear. Why cant MTN send me a final settlement amount on a letterhead so i pay and cut ties with them . This is delaying my bond application . All i want is a legal document with the exact amount i need to pay to settle and i will pay this attach this and the POP and MTN clears my name.