Unfortunately, we do not receive the specific reasons as to why the charge has been declined, as this may involve the disclosure of personal information. We're only told by your credit card provider that the the charge is either accepted or declined.
Please understand that credit cards can be declined for various reasons. These reasons can include that the card is not allowed or has limits for internet transactions. Also if this is an international transaction your credit card may not be set up for that type of transaction or that you have had recent charges that your credit card provider feels are suspicious and they have locked your account.
As such we would encourage you to contact your credit card provider, to inquire as to the reason the card has been declined.