Telkom cellphone contract billing problem

I am so fed up with Telkom. They just want to make money and rip us off. My contract ended in May 2021. Instead of discontinuing my contract they carried on billing me and I was of the understanding that my contract is a 24 month contract so once 24 months lapses the contract should no longer be active, but when I call they told me that I have to cancel it and not them. Which is funny because the contract is for 24 months and not more than that so why do they have to wait for ne to cancel it. Now I renewed my contract and took a R279 contract. They sent me the statement now and I have been billed for minutes 1 July - 31 July 2021 and the contract that I took doesn't include minutes so why am I being billed for minutes. Can I please be billed R279 a month because that is the amount I agreed on.