iCracked Guardian Tempered Glass for iPhone 6

I had this on my phone for two weeks when all of a sudden there is a crack in the corner. I don't remember even dropping my phone so I'm quite upset about that. I'm not sure if it was a faulty cover but it's in such a weird spot and I just don't understand how it cracked like that. I wouldn't recommend.

This is the only tempered glass screen protector I trust with my iPhone 6