Spouting your erroneously understood legalese at us won’t get you a new engine, I don’t think it will get you a new one from GM either but at least they have one. If you were asking the best way for YOU to fix it, that would be a question for this forum, but You are asking how to make GM fix it and asking a bunch of DIYers and mechanics a legal question is almost as dumb as arguing with them abut it.
As I heard my mechanic tell one customer years ago, “Don’t holler at me about your car, I didn’t build it, I didn’t buy it and I didn’t break it. I’m just the guy that’s trying to fix it!”