Ok, there is a dude that vlogs about China that I follow. One of his videos he's comparing his recent trip to Japan to life in China. Dude doesn't know shit (Japan so clean! Japan so safe! Yeah, right).
Well, in the video he talks about getting scammed and posts a pip video showing a female shop keeper ripping customers off with the under-the-counter switch-a-roo. Its actually pretty cool to watch. Look in the upper left and be amazed at how quickly you can be ripped off by someone less than 3 feet from you.
https://youtu.be/iVMbp5-bJAM?t=13m50s
The first customer she shorts buy dumping some of the meat (not sure what it is) into a bag, not giving them the full amount they paid for.
The second customer she simply switches the chicken (I think, or hope its chicken)