Vitality cancellation not being processed

On December 2017 I called the discovery call centre to cancel my vitality account. I was told the "cancellation" department would get back to me in a few days but it is now halfway through January 2018 and no one has gotten back to me yet. Whenever I call Im told that they will call me back no one ever does! This seems to be a common trend because I have noted that a lot of people on this forum are complaining about the exact thing! If this is not sorted I will cancel not only the vitality but the medical aid as well. This delay tactic that they're playing is clearly done on purpose because when I wanted to add a new member to my medical aid it was done in less than a day however cancelling my vitality seems to be dragging. Discovery please don't ***** what was otherwise a decent relationship.