You have to completely reset the watch to enable bluetooth discovery mode.
Sounds like it's faulty @AC1231 ?
Have you tried the process from the manual?
Pairing the Activity Tracker
1. Turn on Bluetooth on your mobile device.
2. Tap the icon of GOJI GO app.
3. Go to Menu » Settings » Activity Tracker
Settings » Activity Tracker (Not paired) » Pair
4. Press and hold the MODE button on the Activity
Tracker until is shown. Press again to
5. When successfully paired, the Activity Tracker ID
and firmware version will be shown.
I'd take it back for a new one @AC1231