On the Credits list (Accounting > Credits), there are a few different filters you can apply to help you find the Credits you're looking for:
The Client filter will populate a dropdown list of your Clients:
If you don't see the name of the Client you need, begin typing in the "Search Clients" field to filter the results.
The Reference # filter is alpha-numeric so you can search for reference numbers even if they contain letters.
The Date filter will search for the date or date range that Credits were entered.
The Refunded filter is a checkbox:
If selected, it will search for Credits that were created as part of a Payment refund.