In Desktop, I created an invoice and applied a payment - invoice is marked Paid.  Then I needed to issue a Credit Memo for the full amount and issued a Credit Card Refund so Credit Memo is marked Refunded.  Customer balance is zero.

In QB Online, I created an invoice and applied a payment - invoice status is Paid and payment status is closed.  Now I want to do the functional equivalent of what I did in Desktop so the original invoice and payment are kept intact, a credit memo and refund are issued and the Customer balance is zero.  How to do this?