Hi i purchased an ipod for my daughter and a $30 itune credit everything was working fine until a sudden message that the account has somehow declined. well after reading all of the post everyone had i took notes and i found out after itune credit was gone the charge went to my debit card i gave when i opened my appleid, but because no money was there and you have to enter the security 3 digit code before it can charge it to your account again. s0 this is how i found out how to fix it.
step 1: by using a pc log into your itune account that has the same appleid log in details.
step 2: click on your user name on the top right and go to account info
step 3: scroll down and click on purchase history, this will give you a list of all the apps you have downloaded and that you have been charged. in red it will tell you what and if you owed them money.
step 4: now if there is amount owing until this is paid your account will not let you download anything even if it's a free app.
step 5: when it is paid or owing balance is gone you can now and SHOULD update the credit card details
step 6: the pictured boxes of the types of card please click on none. this will delete your card detail
" NOW IF I WERE YOU TO AVOID THIS FROM EVER HAPPENING JUST GET AN ITUNE CARD AND STICK TO USING THAT"
I really hope this helped everyone because i know how frustrating it was.