REQUESTED A CONTRACT EXPIRY BUT STILL BILLED

I contacted Thobekila from MTN on the 7th May 2015 notifying him that MTN should NOT renew my contract for my TAB. Hold and behold they are still billing me eventhough I followed the correct process. I called the 808 number and waiting 45 minutes for anyone to answer and I was told that they will still be billing me even though I followed process. They promised to refund my monies asap. To me thats unacceeptable when we are late with our payments they are quick to threaten us with the Lawyers but now they are just expecting us to accept the fact. What happeded to customer service?