Strap mounts broken (Forerunner 45)

I have had my Forerunner 45 since the end of February, so it's less than seven months old and has had very light use. I don't wear it all day, or even every day. Today it just suddenly fell of my wrist - no bags hanging or getting caught on clothes, just fell off. I thought the strap had come undone but in fact the mounts have both snapped in half, and since they are part of the watch body, there's no fixing it. This thing cost me £160 not much more than six months ago, so honestly, I expected better....