Hatchback/liftgate Support Device problems of the 2011 Buick Enclave

The power liftgate door opens 75% of the way when I push button or manually but then starts to closes again. I have bern hit by the door several times already due to doof closing. Also day light on passenger front goes on and off. It will work for a few days then not work for weeks. Have had light bulb replaced and continues to happen.

Liftgate will not stay opened.

Came home from the store , as I was getting groceries out of the back the tail liftgate came down and hit me in the head. Now when its open it jumps up and down. It has a mind of its own. Very dangerous.

The power liftgate does not stay open (the vehicle was statrionary, turned off, and properly parked). Instead it catches and then forcefully closes on whoever/whatever may be right below it. Upon trying to stop the liftgate from closing it will not remain in the open position and continues to forcefully close. This happens every time the liftgate is opened. This is part of a recall (gm safety recall 15240). Documentation received as part of the recall indicates parts are not available to fix this issue. Repeated calls & messages to the service department have not been returned. National traffic highway safety campaign id number is 15v415.