Customer RMA's Blank Title 73007

We incorrctly billed 2 instead of 1 item on a sales order.

A RMA was created in our system (Vantage 8.03.405A)for one of the
items.

A credit memo was created by the system to offset the invoice created
by the incorrect shipment but never showed up on any aging report.

The entrie order shipped, all invoices were paid correctly by the
customer, but if you view customer history in customer tracker, a
credit memo shows open on the system.

How do we clear this credit memo created by the RMA to show it is no
longer open and is not due the customer.

On sales order tracker the $ amount of the order agrees with all
invoices including this credit memo which shows open.

How do I clear this CM to show closed?