being billed for a cancelled contract

Good Day MTN<br> <br> i cancelled mu contract in March, i heve been billed for May, June and noe in July. I cannot get through the customer care center via telephone, i emailed [Email Removed] and got no response, My refernce number for the camncellation is ***. My initial contract was R550 and after cancellation i am being billed an amount of R231. I went to the MTN store (MTN the GLEN MALL)and they told me that there is nothing they can do even though my contract was taken out at that store.<br> <br> Please refund what was debited from my account for May, June and July and stop debiting mu account.<br> <br> I want nothing to do with MTN - service is extremely poor