Different reasons may influence the payment being declined by the Google Play Payment System:

• The card has expired;
• The credit card is over the credit limit;
• The card issuer blocked the transaction for security reasons;
• Your card issuer needs more information to protect your account from fraud.

To try to fix this problem, you can follow these tips from Google Play:

1) Consult Google Center on how to fix payment issues, click here.
2) Call your credit card issuer to verify your identity and confirm the purchase;

3) Make sure your name, address, and payment information are up to date in your Google Play Store account.

Another tip that can be useful: try to make the purchase using your Google account through the cell phone of a friend or family member and, if you process normally, then just install dfndr security with this same account on your cell phone so that the signature is recognized