Listen man. There is a certain power in walking away. Don't give that away. Think about your power for a minute. How much power would it be to hand in a written letter CLEARLY outlining the issue described using MINIMAL WORDS? Somebody would have to look at the situation in detail and if you really deserved to be commended for your honesty then it would come out.
The tables would be completely turned.
1. You would have officially quit. HUGE WIN
2. You would have an opportunity for others to see your side of the story FIRST
3. You may have some chance of coming out on top and even staying with the firm if your letter was written with "much regret" that you absolutely have no other choice because of the hostility and actions of retaliation etc.
4. You can take that letter to the next employer and say I stand behind my actions in a tough situation.
Stay with your power man. You don't want to risk carry around the victim chip forever more you will either be telling this story as a sore loser or as a man with a power and sense of right that can never be taken from you by a "superior".
Bottom line it's victim vs empowerment perspective. In your question post (no offense) you sound like a victim of some one else's actions against you. Really it's just one perspective. Assume the self empowered perspective and they will have no choice but to recognize. Tell the story of how you don't take BS you throw it in the trash.
Fuk you, fuk you, your cool, fu*k you im out.
[EDIT] P.S.
If you really want to step it up and become movie ending cool. You get that letter done up and you walk in with it. You show the envelope to the bad boss and you say in a private way to only him "I am handing this in to watch you suck tomorrows dick".