Over charging

I purchased a car in December and opted to cover my vehicle through Discovery. Little did I know they would rip me off and charge me the incorrect premium. Not to mention the double debit that was retrieved from my account without my permission in January. I have emailed, called, emailed, called and emailed and emailed and emailed and NOTHING. They couldn't care less that they are charging me a premium that is more than what was finally quoted after some negotiations in December. I was being dealt with initially and then, they decided it wasn't necessary to communicate with me anymore. Strange. I want to cancel my insurance. I spoke to Castello Govender today to cancel at 15:13. Let's see if he calls me back.