Mtn makes their problems mine

So MTN decided not to debit for two months and i didn't notice till they send me a email saying i owe R1000,16. I proceed to call and ask, they tell me they had a system glich that didn't deduct for 2 months. Now i have to pay money i wasn't planning to because they failed to do their jobs. Consultants call me wanting their money and when i ask questions they dont know, they give me wrong email addresses to send my complains and no answer.. I really wouldn't recommend mtn and i will make it known that they rob people. MTN DOESN'T EVEN DESERVE A 1STAR RATING.