My question involves business law in the state of: MN

Hi, I am hired by a national company based in MN (they have business activities in all states) as an independent contractor to provide consulting service to their clients. My initial contract was signed in 2005 and was renewal automatically every two years, per a provision in the initial contract. The appintment was renewal just a few months ago for another two year term. The company has recently decided not to pay me the agreed upon fee and to lower the fee by 30%. Can they legal do this? According to the contract, they can terminate my contract without a cause. If I refuse the new term, can they terminate my contract? This comapny has added new terms to the contract twice before forcing the independent contractors to work more hours and to take a pay cut. It was understood then, if the contractors refused the new terms, the contract would be terminated.

Thank you