Discovery Vitality are horrible

I've been paying Vitality for 3 years and never received my vitality card.So this is useless to me,and they refuse to stop taking the monthly fee or to cancel it. Always the same story,the card must have got lost in the mail.So sick of this and there are no way for me to cancel Vitality. Currently paying R370 per month for something that I have never used nor can I use it