I had the standard reply first time but then replied with the all encompassing version that tried to pre-empt their script (I tried X, didn't work. I tried with a different device, strap didn't work, I tried Y and it didn't work. A different strap worked fine with device A and device B, etc) and suggesting that it's just plain broken and that if they give me an RMA number I can send it back and Garmin can send me a replacement. The response was an RMA number and it was all sorted in no time.