Cancellation with M-sure

I want to cancel my bumper to bumper warranty as well as my step up warranty with M-sure, as I have sold my vehicle. I have sent all the documetation required to M-sure in order to cancel my warranties. When I sent the cancellation email to them, I received an automatic response saying that they will reply within 48 hours. It has been 12 days and I have not received a single response from them. When I spoke to the consultant telephonically, she said that they will sort it out immediately once I send through the cancellation document. This is terrible service from M-sure, they quick to take your money but as soon as you want to cancel your warranty, they dont assist you at all.