Lets to through the basics.
1. Try to get any response from it by pressing and holding the power button down for 30 seconds with the battery in and a charger connected.
2. If that doesn't work, try it without the charger connected, then take out the battery and connect the charger and try another 30 seconds.
3. If there are no signs of life, try another charger and perform the steps above again.
4. Finally, see if a friend that has the same phone will let you borrow a battery and see if that is the problem. If it is you can purchase one. If it isn't, your options are down to going through the manufacturer for warranty support or through your mobile carrier.
Won't flicker a light, nothing on the screen, just dead?
How long have you had it?