Billing me with cancelled contract

I have 2 contracts with telkom my samsung mobile and then the 10 gig internet sim card. So we are struggling with the internet signal, so I waited my 2 years as they said and cancelled that 10gig internet contract on the 29th of June 2015. They filled in papers and gave me a number to say that the contract is cancelled. But my contract is still not cancelled and now they are billing me since June. They said there is a delay because they have to find out about the bad signal. But I didn't ask them to delay my contract or anything, I went in to cancel my contract and they wanted a reason, so I gave them one. Now I have to pay because they are delaying it. Now I want to know are they even going to pay the money back? I have phone them but tells me every time they have logged my call and will phone me back! They have never phoned me! Please help me to stop my contract and get my money back!