A Customer should only be removed from the Delinquent List if you were unable to successfully get all invoices paid via Credit Card.
To Remove a Customer from the Delinquent List follow these Steps:
Look up failed Installment Payments:
If you took another form of payment for their order
Select Customer from Delinquent List
Choose the oldest Unpaid Invoice - Gray Totals are Unpaid those in Blue are paid (you may need to click See all invoices)
Click Forgive
You will need to Forgive all remaining invoices
*Once all invoices are forgiven the customer will need to be removed from the Subscription which will stop any future invoices and payment attempts.
Remove a Customer from a Subscription