MTN-Cancellation Nightmare

Getting out of an MTN contract is such a pain. After hours and hours of waiting I finally got through to the cancellation department and I was given a cancellation fee to pay. I paid the total amount and then I suddenly could not be transfered to cancellations department anymore and have to wait for their call back!! almost a week now and no one has called me, what happened to "someone will call you within 72 hours"? Then I called again, put on hold for 1h25min only to be told that "sorry I can't help you, I will send a mail to the person that assisted you last time so they can call you back". & Why is it that when I cancel a contract and convert to prepaid I have to forfeit all the data and airtime I topped up with, surely that has nothing to do with the contract.