I keep reading all those posts about resignations when bosses are assholes. So it's true and I'm not an American. but right now my job lacks workers, and they try to put the weight on us.
So knowing full well that for the life of them they will not fire me, I'm not giving them any more time than I have too, and when they threaten me I just bluntly tell them that they can fire me if they'd like but till then I'm giving my hours when scheduled so they can go figure it out themselves.
stay strong and make a decent pay till you find a better place