Mazda CX-5 sunroof exploded

I drive a Mazda CX-5, 2018 model. On the 22nd August 2019, the car was parked under sheltered parking, on my return I found that the sunroof had shattered. When assessing the car, we found that there was no sign that the impact came from outside. It showed that the the glass was shattered outward, meaning that the impact/force came from within the car. I phoned Mazda Clearwater, where I purchased the car, the manager told me to bring the car in and that they'll make a claim from the warranty. I was even provided a courtesy car. On 27 August 2019, I received a call from the manager, telling me that the warranty doesn't pay for broken glass and that I should return their loan car. Of course I already knew that, from my research on similar cases, it was clear that car manufacturers don't want to take accountability for this. This is clearly a factory defect, poor quality material and it is inconsiderate to people's safety.