Discovery Health impossible to cancel a plan!

Discovery Trauma and Discovery in general are *******. I took out a Discovery trauma policy for a few months and am now overseas. After 3 attempts to cancel the policy via email, all I get is the automated response that they will call me back. I am no longer in South Africa and they cannot call me back. They refuse to reply to my email other than a cyber reply and still deduct he premiums from my account every month. Impossible to cancel a policy. Careful.