1. On POS click on view invoices and find the invoice you would like to refund.
2. Now select the invoice you would like to refund which will open this transaction in cash register.
3. Select the items you would like to refund and hit checkout (green button). If a customer purchased different items you can remove or change quantity. This should also restock the inventory item if relevant items are setup for quantity tracking or start an RMA manually in case of faulty item.
4. You will also be able to take customer signatures at the time of checkout.
Note: RepairDesk doesn't have a specific exchange module, but you can use refund feature for this. Also at this point partial refund is not possible.