Once an order is processed in Linnworks, this action cannot be reverted - for many reasons: despatch notes, stock calculation, order history, and so on. However, there is a workaround which can help you keep your data accurate and print invoices and shipping labels if required.
If the order status was changed on the channel to "Shipped' as a result of Linnworks submitting a despatch note, then first of all you may want to change its status on the channel (on the channel) and inform the buyer that the item will not be delivered.
1. Export today's processed orders - which can be done from the Order Book > Processed Orders screen with the date set to today only and then selecting Download. Make sure that you have the Status column populated by right-clicking on any column name in Processed Orders and selecting the Status column from the column chooser. You can select any other relevant columns from here as well.
2. Open the downloaded file, and remove all orders with a status of 1, as these are paid orders and you need a spreadsheet with only unpaid data.
3. Re-import the orders which you believe will be paid in future.
For example, if some of the orders have been unpaid for several months, then it may be unlikely that it will get paid. For such orders, a return can be done. Once a return is done you can remove it from the file that will be imported.
4. Once orders from the file are paid on the channel, you can print labels and invoices. Once you are done with that, you will need to delete these open orders as the Processed Order records which are already in the system are now valid and the stock levels/financial data is correct.
If orders from this list end up not being paid for in the future, you can simply create a return for the item from the Processed Orders screen as well.