Business ProfileforFederated Mutual Insurance Company

My family, had a family owed business and used Federated Insurance and had a policy on 2 trucks. I started an LLC and I got liability and workers comp insurance with Federated starting January 1 of this year. My families business sold in April and I moved the 2 business trucks from my families policy to my policy. When I got the bill in May, the truck insurance was almost double from the families business policy. They said when you change policies they can charge whatever they want. They would not work with me on reducing it, so on May 30th, we set up a July 1st cancelation date. I also asked them what I owed so I could leave in good standing with them. They told me ****** (liability, workers comp and 2 months truck insurance), which I paid. Now in July, I received a bill for ********. I know I owe a month of insurance and want to pay what I owe. However, my figures come up to around $600.00 for a month of premiums. The bill says "earned premium" is owed. I have called the company 7 or 8 times and talked to various people and no one can specifically give me details for these amounts. I was also told, that cancelation fees are charged industry wide. I have checked with another insurance company and it is not industry wide.I know I owe a month's premium, but I am not willing to pay excessive cancelation fees.