Inefficiency at Vodacom

Trying to cancel my data line, finally been cancelled after 3 months of trying, but they added a new line without my authority, my account should have been R 300.00 lest, it is now R500.00 more. I suspect they do this to show me they are the MAN or to irritate me. Very disappointed. Been a customer of Vodacom sine my first phone more than 20 years ago, I am seining my contract out and then cancelling as they expire. will be going to another network.