Tailgate problems of the 2016 Chevrolet Suburban

The power tailgate comes down with such energized force that myself as a 5'10" adult athlete cannot stop it. Just yesterday it almost decapitated my 10-year old daughter, bruised her head and strained her neck about one year ago I took the Suburban in to my dealer, hendricks Chevrolet and they said there was nothing they could do about it. After yesterday's incident, I scheduled a service call to being it back on tomorrow, March 17th and told them if they did not fix it, we would what other owners are facing the same dangerous problem to force them to fix it, hence why we are contacting you. The vehicle is parked, in stationary position.