MTN I NEED HELP! 😭😭

I am extremely disappointed with MTN service. I took a contract cellphone as well as data. The data was for 24months. It ended in August however MTN still continued with the data of 50G per month,only to find out that I need to make a payment of R1950 for the 50G. I never went to upgrade the data,I was not aware that the term ended. No email, no sms, nothing! The amout has escalated to R6700! I asked them to cancel the data and then I make payment arrangements to pay off the R6700. They suspended both my mom and I phones. I went to MTN Kroonstad and the staff was really being helpful by calling customer care. They say they can't cancel the contract I need to pay R6700 first. If I don't pay it off then they continue adding R1950 to the outstanding balance. When I finally got to speak to someone that works in that department. She refused to listen to me and told me she'll transfer me to the legal department and then dropped the phone. I'm so hurt and disappointed 😥. Called the customer complaint number and no one answered. Now I'm stuck with a bad credit score because of MTN. I wouldn't advice anyone to take out a contract with MTN