Happens when they go to Australia as well. Some of them actually believe it costs $100 to go onto Bondi Beach. And they also get put up in squalid motels instead of the promised luxury hotels. Naturally, they go home with a negative impression of the country.
I went to this one: http://www.bangkoksmiledental.com Just like an ordinary suburban clinic at home. Spoke English. Had 2 white fillings for 2000b, dearer than their advertised price. They didn't complain that I turned up with 4 bargirls and took up their patient seating in the waiting room.