Quote from MakeshIf it says Not Sold in your Completed-tab, then the auction for that item has expired and the item itself should be showing up in the Completed Items-box to the left of your AH-history in the Completed-tab.
If you mean that the item is not showing at all in your AH-history and still can't be found when seached for, then I don't know what's going on.
As I said its showing up in the completed tab as "not sold" on the right hand side, but in my Auctions tab it still says it has over a day left.. meaning its still being sold. Yet when I look for the item on the AH it isnt there.
so either a. its been mysteriously hacked off the AH "somehow"
or b. blizzard have had a massive error and items have been lost.
edit: its also a legendary 50+ so I will be immensely pissed if it's gone.