Hello! I am having the same issue - it seems as if no couriers can get to the lost & found because it is restricted access. Is anyone else flying through Istanbul that could help? This is the weirdest lost and found setup -- I was first told that Turkish Airlines would send it on the next flight and then that I could send a prepaid mailing envelope. According to the lost and found office, neither of those are true. Giving up soon, but thought I would try out my luck here.

Thanks!