I've got your back, @Teeperry72. The instructions below will help you get that amounts off your A/R Aging report.
The Accounts Receivable Aging Detail report shows the total customer's outstanding balances and how long they're past due. Outstanding credits to customer should show as a negative amount in this report. To clarify, did you already record the refund in QuickBooks? After you create a check for the refund, you'll have to link or apply the refund to the customer's credit.
For example, I refunded the customer through check. I entered the Accounts Receivable account to offset the overpayment. Please refer to the screenshot below.

After that, the A/R Aging Detail report should show like this:

To get the amounts off the report, we'll have to link the refund to customer's credit by receiving a zero payment.
- Go to the Customers menu and then select Receive Payments.
- From the Received from drop-down, select the Customer.
- Then, select the Discounts and Credits icon.

- In the Available Credits section, select the check you created and then Done.
- You may see a prompt to Confirm transfer. If you do, select Yes. The amount will be applied automatically to the invoice.
- Select Save & Close.
That should do it! This is how my report looks like after linking the refund to customer's credit:

Additionally, to see the customer's current outstanding balance, ensure to modify the date to Today.
- Go to Reports.
- Select Customers and Receivables and choose A/R Aging Detail.
- Click the Dates drop-down menu and select Today.
Refer to these articles to learn more about running an A/R Aging report and how to write off uncollectable balances:
Please let me know how it goes or if you have any follow-up questions. I'll be here if you need further assistance. Have a wonderful day