We are in an automatically renewing contract, how can we get out early?

What is the name of your state?Wisconsin- We run a small diary farm. In 1997 we signed a yearly contract to ship our milk to a certain company. They just came out with a new policy of paying farms based on volume, so the factory farms will get a whole lot more money for the same product. We can do much better shipping our milk to another company. Unfortunately, the contract that we signed in 1997 renews automatically every December. We were told by the company that we cannot even pay a penalty to get out of the contract. Is there any way to get out of this type of a contract early?