Hi there and welcome
Can you tell me please what exactly happens when you try to make a transaction via the app store?
Can you hold the home and power buttons on the iPad for about 10 seconds until you see the Apple Logo then release.
Let the iPad restart and then try to make a purchase
Let me know the results please.
you are in the united states correct?
Do you have another apple device (iPad or iPhone) there?
ok, the purchase thats failing, it is an in app purchase correct?
Not to actually purchase the app?
ok, have you made a purchase in this app before? And if so, how long ago?
how long ago?
ok, because you did a second one so quick, its likely marked it as suspicious as your card is being accepted by Apple.
You need to wait 12 hours, then try to make the purchase and it should then go through