Hello there, @eawarner1.

First off, I'd like to appreciate you for taking the time to read and follow the steps provided in the thread. No worries, I'm here to chime into this conversation to assist you further in deleting or correcting unused credits and overpayments.

Before I start, would you mind if I ask what product are you currently using? This is for me to provide you with an accurate solution appropriate to your product since the steps are both from QuickBooks Online (QBO) and QuickBooks Desktop (QBDT).

However, I don't want you to go empty-handed so I'm going to provide you on how we can rectify this issue. Since you mentioned that there were no credit memos and unused credits for the customer, let's run the Invoices and Receive Payments report in QBO to check for any incorrect payments and we can then correct the payment there, instead of deleting it.

Here's how:

1. Go to the Reports menu.
2. Type Invoices and Receive Payments.
3. Click on the report to view.
4. You can filter the date in the Report period section or Customize it to view specific data.
5. When done, click on Run report.
6. Locate the incorrect payment.
7. To edit, click on the transaction.

In QBDT, you can consider running the Payments and the Invoices and Deposits they are linked to. Here's how:

1. Go to the Reports menu and select Report Center.
2. In the search field, type Payments and Invoices and Deposits they are linked to.
3. Double-click on the transaction to edit.

For more tips about handling your QBDT reports specifically in personalizing their appearance, open this article: Customize reports in QuickBooks Desktop.

If you need additional assistance with regard to managing payments and customer credits, please feel free to notify me by adding a comment below. I'm more than happy to help. Take care.