Worst service provider ever!

The worst company to deal with! I called to cancel my contract well in advance and was given a ref number. Number was supposed to be cancelled and put over to pre-paid. This did not happen. No, they decided to put the number over to some or other contract without my permission. I will not pay a cent! So, phone MTN then they transfer you to the retention department and someone answers the phone and don't say a word. Instead, you hear how jolly the staff carries on with each other. Get this sorted immediately or I will take this further.