Contract Cancellation

I had a business insurance with them and when I canceled it they offered a lower plan for when I drive other cars since I didn't have a car of my own...and now when I try to cancel even the one I agreed to they are giving me the run around and they are not even covering me for a car that I use on a daily...I have another insurance for the car I drive and need them to stop debitting because when I call them I'm being taken from pillar to post.