Contract cancellation

I have a telkom LTE contract and I have been happy with this contract, I dont use my other data sim card and everytime I go on the telkom app to check my data has depleted. I have another sim card that I use on my router and its 20GB but before mid month it's also depleted. Since last week I've been trying to cancel my contract and no one is will to help me I'm being sent from pillar to post. Spoke to Winile Ngubo and Aphilele Maphumolo but even a Jacky person no one wants to help me. To Telkom I'd like to cancel my contract urgently please I can not be paying monthly for a **** service.