MTN Contract

I am absolutely mortified by my experience with MTN. I had a contract with them for a tablet I bought at CNA about 4 years ago. After about 18 months the tablet broke down. When going to MTN to cancel the contract they advised me to wait till the end of the contract which was December 2019. I then also bought a new tablet from MTN and they combined the two tablets into one account. I asked them again to cancel the contract for the broken tablet no ***. Which they didn't do. After numerous efforts the past few months they still didn't cancel the first contract. My daughter came to assist me the first week in July. We went to Cresta office and explained my problem to Koketso. After being on the phone with somebody at their offices for more than an hour, she told us that she fixed the problem and they would open a new account for me and credit it with the ******** deductions made. Lo and behold! The account is still not rectified! My daughter and I went to their office in Cresta again but Koketso was not there and Mmathapelo attended to us. What a mess. Now I was told to make an affidavit in front of a policeman mentioning everything as well as the different reference numbers given me and they will attend to the matter. I am 83 years old and this is just too much for me. I am a pensioner and can nor afford to waste money. What is wrong with the administration of MTN? The different reference numbers given to me is 285 283 220, 285 284 001, *** and the cancellation ref no is ***. Please, I really do not know what to do anymore