Yes! Notifications are sent for both declined and successful transactions from Apple Pay and Google Pay. These will be visible from within your phone's Wallet.
For an Apple devices:
Go to settings
Select “Notifications”
Select Special Gift Cards
Ensure the “Allow Notifications” is turned on
Customise your “Alerts” according to your needs
For Android devices:
From the Google Play™ Store Home screen, tap the. Menu icon. (upper-left).
Tap. Settings. .
Tap. Notifications. .
Select any of the following to enable or disable: Enabled when a checkmark is present.