I have an article here for you that can help you with some troubleshooting steps for this issue:
Specifically, the section that I believe will help you most can be found here:
Pass not updating
If a pass isn't updating as expected, try the following:
- Ensure that you have an active Internet connection.
- Tap the info icon on the pass and check the last time it was updated.
- If it hasn't updated recently or if it doesn't appear to be correct, you can "pull to refresh" to update the pass.
- Turn on Automatic Updates.
- If it still doesn't update as expected, try quitting Passbook and opening it again. If the pass is still incorrect, check with the company or vendor that provided the pass.
Passbook can use iCloud to keep your passes up to date on multiple devices. This feature is on by default if you are using iCloud, but if passes aren't showing up on your other devices, try the following:
- Tap Settings > iCloud.
- Verify that Passbook is on.
Note: This also turns on Documents & Data.
- Ensure that you have an active Internet connection. If you don't have a Wi-Fi connection, you may need to enable cellular data in Documents & Data to update over cellular networks.
- If the issue persists, try these additional steps:
- Tap Settings > iCloud and turn off Passbook.
- Restart your device.
- Tap Settings > iCloud and turn on Passbook.
Thanks for coming to the Apple Support Communities!