What should people do when governments do not uphold their end of the Social
Contract?

People have the right to change or destroy their government when it does not uphold their end of the social contract.

This is according to the Declaration of Independence, which states:

That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, --That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government

your answer would be just capitalism.