I added gift cards to my apple store and all is gone? how I can find them,
It seems that all the gift cards I uploaded are showing a balance of zero now. How can I find the details for them?
When redeeming a gift card, the amount will be credited to your Apple Account balance and set your Apple ID balance as your default payment.
See -> Check your Apple Account balance -> Check your Apple Account balance – Apple Support (UK)
or
Tap App Store -> tap your Profile (top right of the screen) -> then you will see your Apple Account balance.