I was under the impression that the law's specific purpose was to make them comply, so they don't really have a choice.
The maximum penalty provided by the Defense Production Act is a $10,000 fine, or one year in prison, or both.
The government may also seek an injunction from a court of appropriate jurisdiction to prohibit the continuance of any violation of, or to enforce compliance with, the Defense Production Act, this part, or an official action.