HORRIBLE CUSTOMER CARE SERVICE

So why is it that MTN only seems to respond to customers when they post on this site? I wrote a complaint about one of my numbers that I had cancelled and requested to be changed to prepaid last year after countless times of making the calls and not having it done with billing continuing as usual after it was said that it had been processed to which I received a response saying that someone would handle my complaint. Low and behold the line gets deactivated and I'm told that the incorrect billing issue would be resolved withing 9 days on 05/01/2015. 9 days have come and gone, instead, MTN has since on 30/01/2015 billed me AGAIN and taken money from my account for a number that was deactivated as well? and calling me about upgrading the other line yet they haven't even sorted out the complaint and instead keep taking money from me for a number that is now PREPAID?! When I call the customer care number I get cut off! So what now. And the Katlego lady that is supposed to be handling my query no longer responds to any of my e-mails?