Fox Gal,
I am sorry that she handled it that way...and sorry that you didn't get the pup that you wanted....By the sound of her answer,I would keep checking the local pounds.....sounds like they might have dropped him off and was embarassed to tell you.....
If you like, there is a Great Dane Rescue in Melbourne and Ft.Lauderdale.....donj't know which is closer to you....
you can find them on Petfinder.....go to area shelters....and scroll down....or just look for a Great Dane on petfinder...it will pull those places and what Pups are looking for a great home like yours!!!!