Haunting customer services thats a nightmare

Pathetic customer services. Gosh was horrified when i opened up my email to find a letter of demand from mtn. No other communication what so ever, no email or sms or even a call to query why my 2months payment wasnt made, straight a letter of demand. The amount outstanding to be paid for the 2months was supposed to be R200 but the letter states R1200. So whos gaining this money in mtn on my expense. Worst services ever, when u call the pathetic customer services line oh sisi so sorry call back after an hour we having a problem lines are down an this has been on going for the last 3months. So how the hell do we resolve this issue an prevent our names going bad when mtn lines are forever down????? My opinion is people in mtn are in cahoots with people that *****ing innocent unsuspecting customers.