Credit Memo balance greater than original Credit Memo
It's possible that there are overpayments for other invoices that add up to the customer balance. You might want to review the transactions through a report.
Click Reports at the top menu and select Customers & Receivables.
You can choose Customer Balance Detail or Transaction List by Customer. I'd also suggest contacting your accountant to see if they can recommend other reports that we can use.
Customize the report if needed. Then, review the transactions.
Edit the transactions if necessary to correct the customer balance.
If the customer balance is still incorrect after review the transactions, we can do the Verify/Rebuild process to make sure your company file is not damaged or corrupted. You can use this article for reference: Verify and Rebuild Data in QuickBooks Desktop.
Let me know if you need more help with this. I'll be around.