i feel something sticked to the ground when press brakes

the problem appears when I drive my car on speed starting of 60KM/HR and I suddenly press the brake I hear and feel that their is something stacked in the ground under the left wheel I feel it in the pedals, I already contact the agency of Hyundai Egypt but they said their is nothing every thing is Ok, still this problem repeated I don't know how to solve or whom I have to contact or complain.