So you are unable to double-click the power button to get the Wallet opened/activated? This occurs no matter how fast you try to press the button? If you are receiving the shut-down screen, it would seem that you are not releasing the button enough between presses. Try resetting the Watch. Press and hold the Digital Crown and the power button together until you see the Apple logo and then release. After the Watch reboots, try again. If it still won't work, then use the Get Support link at the top of the page here and speak with Apple Support. Alternatively, if you have an Apple Store close by, use this link to make a Genius Bar appointment to have the Watch examined. Apple will explain your options. Genius Bar Reservation and Apple Support Options - Apple