BLACKLISTED YET I DON NOT OWE MTN A CENT

mtn is a horrible service provider. i discovered that they shortlisted me without even trying to communicate with me. i owed mtn and they handed over my account to saya recoveries, when i got communications from saya i contacted them and told them that i want to find out the total amount i need to pay in order to settle the contract and for my number to be tranfered to prepared as soon as i pay which was on the 15/08/17 and i was told the total amount was around R5.5 which i paid. i even called saya recoveries if payment was received after i sent proof of payment and they confirmed that they did. they even sent legal department of mtn an email showing that i owe 0.00 amount, i was cc'd on the email. i was applying for something last month when i was told im blacklisted and when i called tansunion i was told MTN is the culprit. ive been to their shops, called their lines, emailed all information that proves that all was paid and even a letter from saya recoveries confirming my storybut even to date the issue has not been resolved im frustrated and i dont know what else to do. any assistance will be highly appreciated