Let's say, if you accidentally dropped the item, and it simply disappeared, okay, but if it had been picked up by someone who refused to return it, and afterwards sold it, and the new owner sold it again, and so on, phew @_@ ... for the future, please keep in mind to send in a ticket as soon as you lose the item!
Even if you don't have the ads yet for a recovery, send in a ticket. The item will most likely be traded to a GM character, and in case of a recovery with a fee involved, it will be returned to you.