I know what you are going through with Delta. But though my case ended well, it may not bode well for yours.

Last summer (2011), on arrival in Denver for a few days, I inadvertently left a book in the seat back in front of my seat. (I know--just a book, but it was also one that was being used in some research, with notes in the margins, etc.) I realized that I had left the book on the plane only after we exited the airport and we were in the rental car. We called Delta immediately (using the medallion number) and got hold of a person who told us to fill out a lost and found report, available on line. This person also said that he was filing a report and would try to call the gate agent back at the airport. Once at a computer terminal, we did file a report.

Did we hear anything? No. Not by e-mail and not by phone. Nothing.

However, when we returned to the airport for our trip home, I inquired at the ticket counter about "Lost and Found": I was referred to the lost baggage desk and so I went there. A person was working there who said "We have lots of stuff here and I don't see a book." Well not willing to take her word for it, I asked if I could look through the boxes. She let me do so, and whaddya know: There was my book.

I fear that this may not be any consolation, but perhaps if you can get hold of someone in the airport lost and found, you might have luck.