Apple Watch will not turn on nor will hard restart

I currently have an apple watch that I got from a friend and it worked until recently, when all of a sudden, it stopped charging while it was on the charger. I tried holding both buttons down for 30 seconds and nothing happened, just a black screen. When I plug it in to the charger, it shows that it's charging for half a second, then goes back to black screen. Any suggestions would be appreciated