How do I get out of my health insurance contract?

My health insurance is too expensive and when I signed I was not aware that it was for a year. Now they are telling me I am locked into it for a year.
--------------------
Are you saying that they won't let you cancel it for a year, or that they won't let you make changes to the policy for a year? You should be able to completely cancel your policy whenever you want. However, changes to an existing policy that you wish to keep (such as raising or lowering the deductible) sometimes can only be done during the annual renewal period. Is that the sort of "contract" that you're talking about? That you can't make changes to your policy until your next renewal period? That's the only thing I can think of that would remotely make sense in your situation - you should always be able to completely cancel a policy?
Source