Brand new series 7 Apple Watch won’t change or power on!

Hi I got a brand new series 7 Apple Watch today, it’s been charging for roughly 2 hrs and I’m still getting the green snake of death! I have tried to hold in the crown and power on button for 10 secs but this is still not fixing the issue. Can anyone offer any advise as to what to do? I can’t go back to the shops until 9 am tomorrow.