I am through working overtime !!!

Dan	It's quitting time. I'm gonna clock out now. See you, guys.
Tony	Wait, Dan. Did you work on all the papers and documents we need for tomorrow's brainstorm meeting ?
Dan	Not yet. But I can finish those tomorrow.
Tony	No way ! We need those materials and numbers first thing in the morning. You got to finish them tonight.
Dan	Ugh, I am through working overtime !
Tony	This is business. We have a deadline to meet. And you wont' be the only one under pressure. We've all got to crank out this project tonight.

Explanation :

I am through working overtime - I don't want to work overtime anymore.

Example : I am through with him. [ Do not want to have any dealings with him ]