I definitely understand wanting the last word in, you want to not feel like they are always topping you. Unfortunately you just wont get the reaction you're hoping for. I had my partner cursing and screaming in my face calling me awful names and I "gave him a piece of my mind" and told him no one deserves to be disrespected.

I got a "yes you do".

It's not worth it. If they really want to heal and change, they don't need your words. Your absence is enough. I thought that it would do some justice and change their mind set but it doesn't. They will just become angered at being challenged with the notion of the fact that YOU are calling THEM abusive. YOU dare tell them you don't like their behavior! How DARE you tell them they wrong!