Sorry for youe loss, but this is a lesson. I keep telling all friends that, we never, NEVER, take our watch out of our wrist. Unless we are at home.
If you have the serial number, you must, if you bought from Athens or any other document, it helps a bit.
Call the store, you made the purchase and ask for the details. They keep their records. And let them know for the theft.
Follow any pre-owened sale adverts.
Wishing you good luck, and keep informing us on the developements.