Un point, un trait.
Literally translated as One period, one dash.
Meaning That's it, period.
Although I believe this is initially a french expression, I have heard it in Congo twice in the last two weeks. It is usually used by people trying to make the point that the decision is undebatable. That's it, period. The last person using it was getting excited, with saliva shooting out of his mouth while gesticulating energetically in the direction of a car. I'm not sure what he was saying but I sure wouldn't like to be the one arguing with him. Un point, un trait.