Sway Bar problems of the 2000 Ford Excursion

My SUV drives very unstable at any speed. It seems to bounce while going down a flat smooth road. Bob bell Ford had it for 1 week and finally found the problem when I wrote a letter demanding that they either figure out the problem or give me a new truck. 1/2 hour after my telephone call to them where in they advised me they had no idea what the problem was but that they had the entire truck tore apart, and 1/2 hour after receiving my letter making a demand, they figured out the so-called problems. The sway bar was upside down and they said something about bolts not being put in at the assembly line and that is why we were getting a clanking noise. We picked up the truck, only to have it begin again the next day. If you go over a speed bump slowly or go up a dip, etc. The truck bounces you all over the place, as if it is going to roll. When you put the brakes on it shakes violently, and bounces to the point it is as though the brakes are being bounced from stopping the truck. I am scared something is wrong and it is going to cost my family, me or someone else their life. Ford has no idea what the heck is wrong, they tell us all sorts of off the wall reasons. At first they even said OH we don't see a problem, but then after saying they did not see a problem they tore my truck apart. Explain that, why would you tear my truck apart if you don't see a problem. It took them one week and it still is not fixed. I purchased a $38,000. 00 SUV that vibrates all over the place, is very difficult to stop because of the vibration and bounces when you are driving down the road, in other words I am driving a roller coaster on wheels that is going to come off the track and kill people. If NHTSA can help, we would be truly grateful. Someone has to find out what is wrong with my truck before it kills us or someone else. I want an Excursion, but I am really very scared of this one. Please help us, velma and keith dietz. Thank you.