MTN De*****ing customer

I previously had a contract with MTN. I lost my job and deferred a few payments , once i found a new job i committed to paying the account off. This was once they had handed me over to Shapiro shaik & defries. December 2017 was my last month and i requested a paid up letter from the attorneys which i forwarded to MTN and they claim i have an outstanding balance of R454.17. This is uncalled for and i would like the public to know how MTN still seeks to de***** previous customers. You are actively playing with my credit record. I demand that the account be consolidated and my letter emailed to me. This is the most pathetic service provider!