I can help you with recording this credit card payment, @SLMEM.
You can go to that credit card payment to edit that transaction. Since you didn't know to which card and company this payment was made, I suggest reaching out to QuickBooks Desktop for Mac customer support. They can get into your account in a secure environment and help you trace this payment.
You can follow the steps below on how to reach them:
From your QuickBooks Desktop account, click the Help menu at the top.
Click the QuickBooks Desktop Help menu and select QuickBooks Desktop Help.
Provide some information about this concern in the search box.
Click the Contact Us link at the bottom of the window.
You'll now be provided with a few support options.