Hatchback/liftgate Support Device problems of the 2007 Dodge Nitro

While unloading groceries from the rear cargo area of my 2007 Dodge Nitro, the rear tail-gate (aka "liftgate") , failed to stay in the up/open position and came down at such a rapid speed that the heavy liftgate could have caused serious if not fatal injuries to any small child or adult in the area of the liftgate via trauma sustained to the head, neck, back, or extremities. The vehicle was parked in our garage on level concrete, with no wind/weather involved when this malfunction with the liftgate lifters (2) occurred. The liftgate lifters (2) have not held up the rear liftgate since this incident occurred. I called the dealership for replacement of both lifters. I called the manufacturer of the lifters and they have not returned my phone call. The manufacturer of the lifters is "stabilus, gastonia, n. C. 28052. Ph# 1-704-810-3552 part no. 44831-a, 7121xr0720n 050/07 a 22, 55360915ab.