I’ve done a few posts on examples of how to use return orders in AX. The posting to the accounts is a variable that you might need to look at how you do your reporting.
By default AX will post to the sales revenue account that is used when you post an invoice. This is picked up from the posting setup for Revenue. So when the credit note is posted for the return order it will be to the same account. You can manually change the account on the return order line if you want to have the return debit post to a sales returns account for example. This is manually selected on the line by the operator. Here is a quick walk through.