Telkom is a ****mer

I bought an uncapped sim on telkom,paying R479 every month .. Then they started deducting R579 i called them they didn’t refund me my R100. They continue deducting R479.. This year the sim isn’t working anymore so I stopped using it .. Wrote them an email to stop the deducting and they didn’t stop but continuing deducting on Feb they deducted R879 today they deducted R1801 why is that so because their SIM card isn’t working anymore