Flexicare Discovery Incompetency

I was interested in the product but found out that the doctor I'm currently visit is not in the flexicare network. I sent an email few days after that I want to cancel and then 3 days after I'm receiving a debit mandate. On the automated email I got they said that they will call me within 2-3 business days and way past the 3 business days and there is no response till date. I am well within my rights according to Consumer Act to cancel. They want to drag this thing so that they can charge me. I'm not prepared to go to the bank to cancel their mandate, all they must do is cancel. I don't even want to be busy reversing their debit orders.