It really does take some nerve to post a pic that is not you and then show up at someone's door.   I think the best thing to do when you open the door and realize it's not the girl in the pic is to say, "Umm, that's not you in the pic.  You lied.  Have a nice night."  And shut the door in her face.  

Here's a site which shows some local scammers.   http://phxgirlnextdoor.com/pub/category/rob/

Best of luck.