My phone is not turning on and display isn't working

I dropped my phone and at first the display wasn't turning on. At some points it turned on and in other I all I could hear was the opening and closing sound, the vibrations of the home button. And my mom told me to try turning it off and it isn't turning on anymore I can hear it vibrate but it doesn't seem to respond in anyway. I tried charging it or plugging it into my computer but no answer. Is there any way I could fix it and if not how much would it cost to buy replacement parts or go to a phone fixing service? (Sorry English is not my native language so there might be a few or more mistakes.)