Re: my transaction has been denied.

Hi Yoonjung,

Many times if a card is declined online, your bank has blocked it usually for being out of your spending patterns. You should be able to call the number on the back of your card and tell them that you will be making this transaction and should be able to unblock it.

You can also visit any AT&T store to refill your prepaid account and pay cash.

Hope this helps!