Cruise Control problems of the 2013 Ford Edge

The collision avoidance and cruise control system has become intermittent, undependable and dangerous while driving. There is no way to tell when it is woking or not and to depend on it is asking for disaster. The dealer doesn't seem to have a clue as to what to do about it.

We were returning home via i55 and I turned on the adaptive cruise control and the pre-collision system. Three times in the space of an hour, without any vehicle in front of us, the vehicle brake itself. There was a tractor and trailer next to us and cars behind us on the two lane highway. After the third incident I turned off the pre-collision system but left the adaptive cruise control on. Some time later with different vehicles, but the same types in the same relative positions, the car brake violently, the warning lights in the windshield were blinking and a siren was sounding and there was no one in front of us again. The attempted stop by the car was so violent it threw us forward. We have not driven the car since and it has been at the Ford dealer waiting for a diagnosis and a part that may fix the issue. The Edge has been at the dealer since the the 27th of December and no one has any idea as to when the "part" may be in. We took possession of the car on December 20th, 2014. I contacted Ford asking for a buy back and am waiting to hear. Both the dealership service manager and a Ford field engineer experienced the same issues.