[besiktas]

I was in NJMP Lightning on saturday. bone stock car. 20 min sessions and brand new OEM front rotors and brake pads with 500 light miles on them.
I went on the track and the first session was raining so didnt even push it then in the other 3 session, as it dried up, i went faster but i was still gentle on the brakes. I felt like the pads were not biting the entire day and i dont think i was driving hard enough to boil the brake fluid.
Anyway, at the end of the day, there was a huge layer of brake dust on my front wheels. (much more than the 2 hrs i spent on VIR). On my service info screen, the lifetime of my pads went from 28k to 17k miles.
Is there like a brake in period that i wasnt aware? what happened to them, just fell apart? Were they faulty parts?