NEED ASSISTANCE WITH CANCELLING POLICY

I have a extended warranty cover for my kia sportage with M-sure. I received excellent service from Elias Moshupay but from the customer service department the service is non existent even Elias email them to assist me without any success. I have sent numerous email which has been delivered and read without any assistance. Their service delivery is pathetic. I need to cancel the policy because my car is sold but I probably have to change my bank account now in order to stop them from deducting money. Please think twice before you use them their customers are not important to them at all.