I have the same issue and no matter how i chance the billing address, redid the International Region, i entered a credit card and all the information just like on the Credit card bill and still it does not take me further after creating the card. I have also re-logged my phone using the apple ID after signing out and restarting the iphone after powering off fully and re-synchronizing with the app store. I have also deleted the cards app and re-downloaded the app to see if that was the issue.
It give me the same error.
" Login Failed: There was an error signing in. Please try again."
I am using an iphone 4S and the same credit card and contact info and my user name has worked in the past where i have sent cards a couple of months ago. So i am not sure what is causing the issue now.
If anyone knows please let me know.