Why am i still being bill, I cancelled my contract

In March 2015, I walked into the Gardens centre branch, had to hand write a cancellation letter in order for my contract to be cancelled.<br> <br> Low and behold 8 months down the line you F&*^king retarded *******s are still charging me with a reduced amount and I cancelled my contract because MTN has the ***kest service that I have ever experience and now you *******s still continue to charge me for a service that I cancelled. How difficult is it for your consultants to handle a simple cancellation request, what kind of employees do you employ that cant finalise my request adn why the **** are you still charging me for you *** service.<br> <br> As my contract expired in March 2015 and I walked into your branch to cancel my contract. I want an explanation as to why I am still being charged and I want the funds refunded to me which you *******s have been *****ing from my account. This is theft especially after I cancelled your *** contract and why your service is appalling.