What can I say: THANK YOU SO MUCH !!! sağ olun (beyond) Teşekkür ederim

rozy is a superstar and deserving of the highest praise.

I am also extremely thankful for the assistance provided by others in Istanbul.
Unfortunately for someone not physically present in the city, this is indeed an uphill slog. Likely needlessly impossible for someone without friends, colleagues, family, nor forum members in Istanbul.
(See: Lost MacAir laptop at Istanbul)

It might take someone at the level of the airport manager or head of Turkish Airlines to alleviate this difficult means of handling lost items.
I also have no doubt that are various cultural and possibly security issues at play here as well. However, there should be a means to address these and provide relief to a customer. As noted in the above url, I was also told by many folks that they cannot physically retrieve lost items from the Domestic Terminal, which is where they are sent.
For lost items from International flights, having 2 offices to handle such items, one perhaps near the CIP lounge, inside the secure perimeter, and 1 perhaps near a Ticketing or baggage claim desk along with someone who can be paid a small amount to get an item from 1 place to the other would be ideal. Perhaps this can be incorporated into the new airport design. Similar strategy for Domestic flights would seem appropriate.