are all your volumes up?
if yes then:
1)Turn off your headset
2) turn off Bluetooth on your phone
3) remove your device from the paired devices
4) soft reset
5) add new BT device
6)put on pairing mode on your headset
7) select your device from the list and just press continue. Check the Stereo Headset option
After the pairing has been done.
Play your music..