Try to pair it with another device so you can diagnose if it's the blutooth of your LG Headset.
By the way, my experience with LG Headset is that it won't pair withh all bluetooth smartphones.
1, Are you sure you connected it to an electric outlet with power?
2. Is your charger working? Devide shond have some indicator it is chaging, loke a flashing LED. Read what it says in the manual
3. If everything fails, might be a defective unit. Take it back where you bought it to claim warranty service