Made The Purchase Using Your Mobile Phone:

When using your phone as a payment it changes the last 4 digits of your card for security purposing, listed below are 3 examples of how to retrieve this number

Apple Phones:

How to find your Apple Card number
Open the Wallet app on your iPhone.
Select the Apple Card.
Tap the ellipsis button (the menu) on the top right.
Scroll down to Device Account Number and place this number in the box below. 

Samsung Pay:

Open Samsung Pay on your phone. Tap Menu, and then tap Cards. Next, select your desired card. The last four digits of the digital card number will be displayed next to Digital card number.

Samsung Favorite:

You can also see your digital card number when you access your Favorite Cards in Samsung Pay. On the Favorite Cards screen, the digital card number will be displayed next to the card.

Other Phones:

Please google on how to retreive your digital card number