To get it to charge, please try the following.
1. First remove battery from phone.
2. Next plug it into the charger.
3. Now turn on the phone.
4. Once you are past the boot screen, insert the battery (about 5+ seconds after you turn it on).
5. You should now see a steady red charging light and it should start charging.
6. Be sure to let it charge for a few hours before trying to use it again.
If this doesn't solve it, you may need a new battery.