Try pressing the home and power button at the same time but holding it down until it shows the apple sign. If that doesn't work you can rest your iPhone before sending it back for a replacement.
1- Hold down the home and sleep/wake button at the same time (In order to power off that way)
2- Once you were able to power off, next hold down on the home button and at the same time plug the USB cable into the phone and computer. Keep holding the home button until a message factory settings. It will take a few minutes for it to appear.
3- Once it does click on restore.