To perform a return:
This will create a Return in the "Waiting For Customer" status and create a Purchase Order for receiving. Once the PO is received, the Return will automatically update to "Received From Customer". At that point you can edit the Return and move it to "Closed".
You can view all Returns under "Orders/Returns". By default, it only shows "Open" returns. To view "Closed" return change the "Status" to "Closed" and click "Filter"