Underbody Shield problems of the 2002 Oldsmobile Bravada

2002 olds Bravada (which we have owned since 9/2004) was being driven by my teenage son (with 3 other kids in the vehicle), as he left a stop sign, the frame of the vehicle broke loose from the body, separating the control arms from the frame and dropping the rear of the vehicle. He was traveling approximately 20mph at the time of incident. He managed to get to the side of the road where the vehicle came to rest in a ditch, a semi-safe distance from traffic. The vehicle was towed 11/10/12am to a nearby gm dealership. The estimated cost of repair begins at nearly $7000. , which would exceed the vehicles value. The gm dealership, to which the vehicle was towed, has advised us not to repair the vehicle as it would be too extensive. To further that statement, the gm dealership has discouraged us to even obtain a full and accurate quote as this would take too much time for a vehicle that should never see the road again, agreeably. To quote both the tow truck driver and the general service manager of the gm dealership; "they have never seen a vehicle with an issue such as this. " repeated attempts to report this to gm have failed. In efforts to minimize personal opinions from this post, I will only say this is utterly unacceptable on the part of gm, and a safety hazard to unsuspecting customers.