Are the credit notes subtracted from my total years sales even though I never returned cash to the customer?

I have a publishing company. I invoice customers for future services (a year of publications) and customers are on a monthly payment plan to pay off their invoice.  I decided to close the business so I applied credit notes to customers with outstanding invoices (for future publications they would not receive). Are the dollar amounts of the credit notes subtracted from my total years sales revenue even though I never returned cash to the customer?