View the list of Sample Business Letters Reply Cancelling Unfilled Order Disclaimer: Be aware that some of these sample letters have legal, financial, or other implications. If you are not sure about the use of any letter, consult with an appropriate professional first. Reply Cancelling Unfilled Order Dear I am in receipt of your correspondence noticing us that there will be a two week delay in the shipment of the above referenced merchandise. This delay is unacceptable and we are therefore cancelling our purchase order number (number) for the above items.