Why won't my phone turn on?

After not using my phone for a couple of hours, I realised it had turned itself of. I figured it might be low battery, so I let it charge, but I still couldn't turn on my phone. After that, I tried to take out the battery and press the power button for a minute, and then put the battery inside and turn on the phone. When that didn't work, I tried to boot it in recovery mode by pressing the power button, volume up and home button. I got no response. I have also tried two different charges, so that's not the problem. Really don't know what to do, so if anyone could help me that would be great!