If you think you're being treated unfairly by an insurance company you have a couple of options.
Complain to your state's Department of Insurance
Each state has a Department of Insurance whose job it is to make sure insurance companies treat customers fairly. They can investigate your complaint and, if they agree with you, force the company to change its behavior or pay a fine.
Sometimes, even just telling the insurance company that you're planning to contact the Department of Insurance will make them change the way they're treating you. Find out how to contact your state Department of Insurance.
Hire a lawyer: This is the strongest action you can take, but it's also the most expensive, time consuming and risky for you. So you should feel strongly that the end result is going to be worth the time and effort before you hire a lawyer. Sometimes, even telling the insurance company that you're going to hire a lawyer will make them change the way they're treating you.
However, insurance companies are also used to getting this threat so be diplomatic. Consider saying something like: "I would really like to settle this without going to court. Is it possible for you to improve your offer so that we can reach an agreement that we both think is fair?"
Find out how to get a lawyer