Cancel my lapsed contract

I am trying to cancel my contract with Cell C as it expired in the 1st March. I have called their cancellations department numerous times but I keep getting transferred from one department to another,everywhere except the cancellations department. Do you even have a cancellations department Cell C?.I owe you nothing!!! You rather have agents calling me 5 times a day for an upgrade even though I have clearly explained that I do not want one !!!