Headphone pairing

Hi there

I have had no success with pairing my garmin 245 to even a brand new suggested pair of headphones (plantronics 3100). The watch will occasionally be able to pair with the headphones but in these rare occasions still no music plays. I have tried everything-turning phone on and off, repairing (mixed results) and still zero luck. Can someone tell me whether we should just return the watch?? Ive now spent money on new headphones which dont even help and is slightly infuriating.