Vodacom not cancelling my contract

Hi have been trying to cancel my Vodacom contract now for the last week and a half and absolutely nothing has been done. I have sent numerous emails and spoken to a consultant that have me other contact details and still nothing. I have made it clear I can only be contacted via email and. That I have left the country and no longer require Vodafone services. I have sent every single little detail that would be required as proof that I am the account holder so that my contract can be cancelled. I'm beyond fedup with this incompetency now, and will NOT pay any further premiums as my contract period has expired long ago and is only on a month month basis now.