Threatening me after cancelled contract!

In June 2015 I opened an unlimited contract with Telkom. 2 days after opening it I cancelled it (WITHIN THE COOLING OFF PERIOD) because I was sold the contract under false pretenses.<br> <br> It took Telkom 7 months to cancel this contract! I am now being constantly harassed that I need to pay R5000 for usage. I SHOULD NOT HAVE TO PAY THIS as I cancelled my contract in the cooling off period. The fact that it took Telkom 7 months to cancel it after MANY emails begging them to cancel it is NOT my problem. <br> <br> I am now getting calls from debt collectors, and I have told them I am awaiting a call from the billing dept head as I have instructed MANY call centre agents. This needs rectification but I WILL NOT PAY! I am protected by the National Consumer Act and am willing to go to court!