Hatchback/liftgate problems of the 2008 GMC Acadia

The contact owns a 2008 GMC Acadia. The contact stated that there were no failures until the vehicle was taken to the dealer and repaired per NHTSA campaign number: 15v415000 (structure). The dealer indicated that they completed the recall repair, but the liftgate came down twice without warning. The failure bruised someone's head. Medical attention was not required. The dealer was notified of the failure and provided no solution. The manufacturer was notified that the recall remedy failed to provide a solution. The failure mileage was not available.