Iphone 5s screen isn't responding after iOS 9.0.2 update

I UPDATED MY IPHONE 5S TO IOS 9.0.2 AND WAITED FOR IT TO FINISH UPDATING. I HEARD MY PHONE VIBRATED AND THOUGHT THAT THE UPDATE WAS ALREADY FINISHED. SO THE PHONE RESTARTED, WHEN I WAS ABOUT TO ACCESS TO CHECK THE NEW UPDATE, THE WHOLE SCREEN ISN'T RESPONDING AND WORKING. BUT ALL BUTTONS AND SIRI IS RESPONDING. I DIDN'T DO ANYTHING TO BOTHER THE UPDATING PERIOD AND I WAS JUST SHOCKED I CAN'T ACCESS THE PHONE BECAUSE THE WHOLE SCREEN IS NOT RESPONSIVE. I TRIED TO FORCE POWER OFF THE PHONE BUT ITS NOT WORKING. PLEASE HELP!