Tracker refuses to cancel policy of member who immigrated and sold car

We are busy with immigration. I have already been away from South Africa for 4 weeks. My wife and daughter used our car, on my name; and sold it before they leave South Africa. Now the car is sold, my wife phoned tracker, and they gave her email address 0TEX Retention Consumer ********** and said I can email the cancellation, as they wont accept it from my wife. Then we got a reply email, to say that I must phone them in person to cancel. I rep****, they can then call me on my New Zealand cellphone number, and they should also bear in mind there is a 10 hour time difference. I have not had any response again. My wife has signing rights on my bank account, and I told her to go block the debit order. I mentioned this in the email aswell, but Tracker does not care. PLEASE CANCEL THIS POLICY NOW!!!! We do not have this vehicle now. How is it easier to sell a car, but you can't cancel the tracker!!!