Send that to someone who fixes watches. Maybe all it needs is to get cleaned. If the buttons are working then try reseting this way.
# Press and hold the '''Power''' key until REBOOTING displays at the bottom of the screen.
# Press the '''Power''' key repeatedly until the Select REBOOT MODE screen displays.
# Press the '''Power''' key to highlight ' Recovery'.
# Press and hold the '''Home''' key to select.
# Keep holding the Power key until the Gear S3 begins rebooting.