You should be able to delete, but have they been paid for? If not you must do something,the correct proocedure is after 4 days you cancel the sale using reason "Buyer has not paid".
If they have paid you can't keep the money, and the Code is not absolutely essential. It would have been sent by Text to buyer, but that does not mean you cannot mark as dispatched. As said you must do something, otherwise you will have cases opened to get refunds.
