I think you must be confusing me with an idiot.
The government did not sign any contracts, they wrote a law dictating what insurance companies have to do. If that law is flawed, which it is, the government has to deal with the consequences of making a stupid law.
I worked as a volunteer for the local church helping needy people sign up in my community.
There were so many problems with the sign up, but specifically, the 2 local Insurance companies that did choose to go on the exchange, (in my State, there were only 2) Would not issue an insurance policy to anyone needing subsidies, without the Gvt exchange transmitting to them, the policy chosen, the amount towards the premium guaranteed by the Federal gvt, and the amount the policy holder needed to pay each month, and a Federal Authorization number...and even if they had a paper copy sent to them from the exchange, with the federal authorization number included, with the guaranteed amounts on it that they could show the insurance company, the insurance company would not set up a plan for them, until they got their electronic transmission from the Federal gvt with the guaranteed amount from the federal gvt. and authorization number.
I did take a course in Contract Law when in college, and granted that was many moons ago, but if memory serves, that will hold up in court as a Contract between the two/three....
So, I think the gvt will have to honor that contract, for the full year of the policy...if the other parties are honoring their part of it.