iPhone 4 not turning on

Just got a new iPhone 4 the other day. I was charging the phone and it fell, only a couple feet at most. There is a small crack in the back of the phone now, and it won't turn on anymore. My friend has a iPhone 4 as well and we swapped out the battery and the back housing (just to make sure that the crack didnt short anything out) but the symptoms persist.

I have it plugged into the wall charger now, tried doing a hard reset (holding home and power for some time) but nothing. This is very frustrating to think that the iPhone 4 is this fragile. Does anyone have any suggestions that I could try to get this device back up and running? Any help at all would be very appreciated.

 

thanks. I will go to an apple store if I really need to, however the closest one to me is several hundred miles from where I live. I am a little nervous that they will say my warranty is voided from the damage. Before I go to the store, I was hoping someone may have a suggestion that I can try at home first other than what I had mentioned. Thanks a lot!