well i got this email,which means that it was declined due to insufficient balance though their can be any other reason
Greetings from Amazon.com,
We're writing to let you know that we are having difficulty processing your payment for the above order.
To protect your security and privacy, your issuing bank cannot provide us with information regarding why your credit card was declined. Since we cannot process payment at this stage, we have canceled your order. We apologize for any inconvenience this may cause.
We encourage you to place a new order with an alternative payment mechanism, if possible. You can find all of our available gift card options here:
http://www.amazon.com/giftcards