Super bad service

I took a contract in August 2017 and it ended August 2019, then I received a call to be on a month to month contract where I'll be getting only airtime I agreed. 2020 March I lost my job n couldn't continue paying. I got a job in December 2020 I called mtn only to learn that my account was handed over. I called the firm and paid up my debt. Then received a paid up letter. I called mtn and advice that my acc is paid up can they unsespend my number and remove me from the contract to prepaid. It's been four months of up and down still my line is suspended. I called more than 30times with no help they keep o' telling me I am on the old system then traaansfer me to other agents and the logged a ticket with legal but nothing happens I have over 20 reference numbers to no assistance.

I paid in full but I can't make or receive calls, my name is o' default status with ITC I don't know what to do anymore.

Bad service extremely bad.