incorrect billings for 3rd month in a row

This is the 3rd month in a row Telkom Mobile is incorrectly billing me. Case no ***3 and ***4. Both times my case was handled by Given. Everything gets sorted out until I receive my next month's bill. How can I have an overdue balance when it's a debit order? I did not sign up for a Add On Internet Bundle. Can Telkom please sort of their issues or can we just cancel my contract.? I don't have the time to be fighting about mistakes Telkom is always making. My wife is on Vodacom and she never has these type of problems. <br> As usual Telkoms media team promise some1 will contact me but not does; why the lies?