problem with app store and payment

Hello. I got a itunes/app store gift card. I redeemed it and tried to purchase an app. After i entered my touch ID, it says "verification required. before you can make purchases, you must go to settings >ITunes and app store >apple ID and verify your payment information". I clicked on continue it opened the settings, double-tapped the apple ID balance, and added the funds, but still it says the same things, even with a free app. Any help?
Best regards
Maxi