Vodacom not honoring a data contract cancellation!

I phoned the *** line as instructed in January to confirm cancellation of a 24 month contract which was completed by end February 2023. I also emailed the customer number to confirm my instruction. Imagine my disappointment when they blithely continued supplying data and debiting my account in March...and April! By now they were charging a penalty of 50% of my contract value. Various telephonic conversations later, they advised me that since I had been supp**** data I must pay for it! (This is a destroyed card) Needless to say, I have handed them over to the National Consumer Complaints Council to sort out. It is surely a ******** act to continue debiting an account after cancellation?