Did anyone even think that maybe the breeder did receive the dog and it died and to releave herself of replacing it she said it didn't arrive. And furthermore why would the owner leave the dog in the airport if it missed its flight, my heart and prayers go out to her, but I would never leave my dog anywhere over night especially an airport. Airports do have surveillance cameras maybe someone stole the dog.
But if the dog was not eating at 3 months I fear she wasn't healthy, I've bought puppies when they where only 6 weeks and they eat just fine. When a dog is not eating its usually sick, I feel she should have took the dog to the vet unfortunately there are many irresponsible breeders who only care about the money. I bought a dog recently and now I'm in court suing her because she refuses to replace the dog. The dog was sick with pnemonia or parvo and I'm sure she knew but just kept quiet so she could get the money. This was a woman whos been breeding for 25 years and claims she loves her dogs. Here the law states its 41 days after the purchase considering you take the dog to the vet within the first 3 days you have the dog. Don't give up and keep pushing to find out what really happened.
Best of luck and you are in my prayers.