CX-9 with broken door

The front passenger door on my 2012 Mazda CX-9 is very heavy and when opened on a hill the clip holding the door snapped. This caused the front door to swing open really far and has caused damage to the door. When we took the car to the dealer they said it was because of the weight of the door, but all claims are dealt with by them sending a photo to head office where it's approved or not without even looking at the car. They didn't get back to us for a couple of weeks and then said it broke due to 'excessive force', so it wasn't covered under warranty. They won't even discuss the matter or look at the car in person. Have you heard of any similar problems with these cars? I am so extremely disappointed in the way they deal with their customers.