[OHNE G-Nachweis]
When I tried to wind up, I only managed to wind it once before it made a 'twang' sound like something snapped. After that the button had no resistance and was not doing anything and the coil completely unwound.
The watch completely stopped moving and I could not use it at all and trying to turn the wind up button made no difference and did not do anything.
This was the second time I have wound the watch up and I did not do anything other than try to wind it up not even changing the time. 
I am sending the watch back to either be replaced or refunded either is agreeable to me