If a deposit is declined by your payment provider, in most instances this can be resolved easily. You could consider the following:
You can review and amend your payment details on the Deposit page.
Your CV2 is the last three digits on the signature strip on the back of your card.
For reasons beyond their control, some card issuers may block transactions to gaming companies. They would advise you to contact your card issuer in this instance.
If you have any further problems when making a deposit, please contact them and they can assist you further.