Unable to on my mobile A33 display by power botton

After unplugging my phone from charger in the morning my screen unable to display anything it was dark but after it screen display on and I started to use wi-fi then so many massage was entering while I am scrolling on my telegram page and then suddenly display is off and unable to on it from the power button still I am surprised why this happened my mobile did not fall and the screen didn't have any broken sign on it

Why this happened ?please help I still unable to use it and there is sound when I plug in to the charger