Bill Management - Adjust Invoice Rather than Issue a Credit Memo?

Summary: My client is looking into implementing the bill management portal. I understand when an open invoice transaction is disputed by the customer, they need to click on the "Request Credit" button and fill out the dispute form. This then automatically goes down the path of possibly issuing a credit memo. Is there a way to configure the system so it adjusts the open invoice instead?

(Yes I understand if the credit memo is issued you can apply it to the invoice to adjust the open invoice balance, but that is not what they want their customers to see/process.)