New and in need of help

If one end or the other is turning in the mounts, it won't jack up. If the torsion bar is broke, same thing. Maybe it is just weak, which may explain why someone let the car down, just to keep it level. Jack it up, take the wheel off after supporting the car, then crank the bolt as tight as you dare. you decide. Then get a large lever and gently pry the control arm down. Between the lever and the bar maybe you will at least be able to free it up. I wouldn't put my head under the control arm, it could go down all at once. You could even put a stand about an inch under the arm so as to limit its travel. If it goes down a little, you could jack it back up, then let it down a little more than the first time. Sort of just ease it down instead of trying to move it six inches in one direction all at once. And look for things that may be binding the suspension. I've seen blocks of wood stuffed in some. I would undo the shock if it is on, just to eliminate it from the equation.