Details:During the purchasing process the message is displayed and you cannot proceed with your order.
Solution:This means you have already used that credit card on a PayPal account so in order to
use that specific credit card you have to login to your PayPal account.
If you do no want to login then you have to use another credit card that is not attached to a PayPal account.
Need more help?
Contact paypal at: https://www.paypal-community.com