Never open an account with MTN

Here we go again, my name has been blacklisted because of MTN, since they started over charging me for high internet usage that I did not use, I try to request them to send me a detailed report of the sites I visited and they never sent me, I had a modem(open line) which they used to give me 2GB and I was paying R119 per month but one other month the bill came at R1000 something then I asked them how as I did not use the modem as often and they failed to explain , and as a results they blacklist me, it just recently happen to my wife who they she got overcharged on her contract which when she open it was not an but she got charged way more than what she was supposed to and she also asked them to check and get back to her but they have not so they blocked her sim card as a results. MTN are bad guys and please be on the look out of their shenanigans.