Tailgate problems of the 2011 Jeep Grand Cherokee

This is for a 2011 Jeep Grand Cherokee laredo (< 6 months old) the Jeep had been parked outside on a warm day. I went to go open the tailgate, and the tailgate only opened part way before stopping. I then nudged the door open so it would go all the way and the glass on the tailgate exploded, cutting two of the people standing behind the vehicle. At that point the tailgate opened all the way and the spoiler at the top came off. I contacted the dealership who submitted pictures to Chrysler. Based on pictures alone, they stated that they could not determine that it was a manufacturer defect and therefore denied my claim to cover under warranty. I was instructed to contact the company customer service line and request that they send someone out to take a look at the car. They never sent anyone else out. Apparently the district manager looked at the pictures and the description of what happened and made the decision to not cover it. Chrysler claimed they couldn't overturn the district manager's decision. They strung me along for 2 weeks over the phone to tell me this. There is really no other reason than a defect that would cause this to occur.