Telkom has hands in my cookie jar

I had a contract with Telkom and it came to an end in October 2019 and I went as far as cancelling it to stop future debits. To my horror every month subsequent to that they are deducting about R384 per month and I have to reverse payments every month. This is disgusting behaviour as I have no relationship with Telkom anymore yet they’re still making my life reasonable which is why I left them in the first place. I’m even contemplating a legal recourse because this tantamount to harassment and financially prejudicial to me and my young family.