Please find steps below on how to delete the current credit card information on your account:  
1. Access Google Wallet 
2. Sign in to your Google account if requested by the site 
3. Select “Payment Methods” on the left side of the page. 
4. Any linked credit cards to your Google account will appear 
5. Select “Remove” 

For more details on how to manage your payment information, click here. If your issue persists, you may contact Google Play Help Center here