Multiple stores and transferring a credit

Welcome to the QuickBooks Community, @DaveBHastings.

I appreciate you for providing details of your concern. So since you have created a $0.15 Credit Memo, make sure that you Apply Credits so it will be applied to the invoice including the payment. 

If the option to apply credits is unable, here are the steps to fix balances that are result of an underpayment.

Create a General Journal Entry to write off the amount

1. From the Company menu, select Make General Journal Entries.
2. In the Make General Journal Entries window, change the date and fill in the entry number if necessary.
3. Select the Account field and select Accounts Receivable.
4. Enter the amount under the Credit column, tab to the Name column and select a Customer Name from the drop-down list.
5. In the next line, select the offset account and enter the amount under the Debit column.

For more details, please refer to this article link: Write off customer and vendor balances.

Also, I'd be adding a helpful article that may help you when you have QuickBooks Desktop concerns, such as managing your account, set up and process payments, etc. This will help to keep your business to run smoothly: QBDT Help articles.

Please feel free to leave a reply below if you have further QuickBooks concerns. I'm always here to help you. Take care always.