Poor customer service!

I had sold my car in June, requested for a cancellation of policy via email, no one responded to my email. Months later after continued charges I sent a follow up email I was told they had received my email then, but chose not to do as I had asked regardless of my request. I’m now being charged 6 months extra for a car I don’t even own. I requested for my account to be rectified. And I still haven’t received a response till this day.