this app is a scam.
I have tried everything, no cards are redeemable, support doesn't respond, I tried to go to the support page and it wasn't functional. Nothing works, yahoo has became trash and I am deleting this app A.S.A.P. and I reccomend anyone reading this does the same.
We are sorry to hear you are experiencing issues with that Yahoo Play app, please email out support staff at email@example.com so we can assist you!