Your bank sometimes may place restrictions on your ability to make payments internationally.
The easiest solution is to try another credit card or payment method available on your account.
In most instances, credit card restrictions can be removed by getting in contact with you bank or financial institution and requesting them to permit international transactions.
If you are still having problems depositing, please lodge a support ticket.
Be sure to include details of the transaction such as card type, amount, first 6 and last 4 digits of your card (e.g. 456789xxxxxxxx7879).