From time to time someone will give you Credit that you don't want to accept for one reason or another. When you click through from the email notifying you of the new Credit, you can choose to "Decline" the Credit. You can also vist your "My Credit" page and visit your "Inbox" area and click the trash can icon to decline the Credit.
Declining the credit or clicking the trash can option both permanently delete the Credit. It cannot be recovered once deleted. If you are not certain you want to delete the Credit, you can accept it and mark it as Private (using the eye icon). That will keep the Credit in your account, but will keep it invisible to other users until you deice whether you want to keep it or share it.
If someone sends you Credit that you feel violates the Credly Terms of Service, please report the Credit as "abuse" using the "Report Abuse" link that appears on the Credit accept/decline page, and the Credly team will investigate.