Refusal to cancel contract

My contract with cell c ended in August 2017, the premium was R79.00 a month. i called them in July to cancel the contract and they agreed. In September they debited R145.00 from my account,.i let it go thinking that maybe i still owed them, this month they have debited R195.000 from my account...when i called the call centre they said that the contract was not cancelled and i had extra services thats why they had been taking money from me. Today i called the call centre to cancel the contract I kept being transferred from one person to the next, the operator told me that I should call during office hours (8am -6pm) and then the call was cut, the only problem was that i made the call at 14h20. I am extremely disgusted by this horrible network and what angers me the most is that its not the first time that they provide such appalling service.