Thanks for dropping by the Community. I can help walk you through pulling up a report that you need in QuickBooks Online (QBO).
You can pull up or run the Transaction List by Customer report, and customize it to show all the refund receipts that you've processed for the year.
1. Go to Reports menu at the left panel, then type Transaction List by Customer on the search bar.
2. Click Customize on the upper right.
3. On the General drop-down, select the appropriate date on the Report period.
4. Now go to the Filter drop-down and choose Refund on the Transaction Type drop-down.
5. Pick a specific customer on the Customer drop-down, then Run report.