Vodacom keeps steeling my money from my bank account

This is my second complaint within two months about Vodacom. They are still deducting money from my account for over 3 months. I have cancelled my contract at the beginning of November as a notice period which expired on 14th December 2020. Yes, an investigator phoned me and said he would stop the debit orders and refund me, but no refund and they are still deducting money. Nothing has changed. The amount is less now but it's still *****ing money from my bank account.