Refunds, returns and cancellations
These are three separate steps: a refund moves money, a return records goods coming back, and cancelling stops an order that hasn't shipped.
Refund
On a paid order, press Refund, type the Amount and press to confirm. The money goes back through the same payment company, and you can refund part of it. Cash on delivery can't refund through ShopNx, so give that money back yourself.
Return
Under More actions, press Record a return and tick Restock on anything going back on the shelf. This moves no money, so refund separately if you owe it.
Cancel
Under More actions, press Cancel order and give a Reason. Its stock goes back. You can't cancel an order once it has shipped, and nothing but the note can be edited on a cancelled order.
Unpaid orders
An order that is never paid expires on its own and its stock comes back. Where the payment company can be asked, ShopNx asks first, so a paid order isn't cancelled because a message went missing.