MTN are ************s!!!!!!

MTN You are ************s! I had 2 capped lines. Suddenly the one account jumped up by R400 this month. when i phoned to query a VERY rude consultant told me it is an uncapped line. I told her to look at the history, and see it was the same every month for the last year. She gave me some stupid story about me being sent a msg to a modem number to change some setting from a 0 to a 1. How do you send a msg to a modem???? Why not send it to my cell?? i cant see msgs on a modem. So MTN kindly uncapped the line, and my son unknowingly used the phone because in the past it was capped, and he had to pay for top up airtime, and now I have to pay. MTN you are a lot of *******, and your service is terrible.