Why has my credit/debit card been declined?

The reason(s) might be below mentioned problems:
1. Your card information is not valid.
2. You don't have enough money in your card.
3. Your card doesn't have "3D secure" code. We would like to inform you that "3D secure" code is NOT a CVV2/CVC2 code which is written on the back of your card. Please, contact your bank to get "3D secure" code OR use another card with "3D secure" code.