Years back learning how this game works, I would just accept the bait and take the switch but its been a long time now since that is my status quo. And certainly the reviews here have helped immensely in that regard. If I am TOFTT and visiting a new provider I have a screen shot with me of the ad and pix and if what is in front of me is just not what I expected I simply say, I was expecting THIS woman. Then the usual excuses etc, I just say sorry there has been a mistake made in your ad and I walk. I have enough regulars in my rolodex (you young ones look that up) that if the urge is high, I can find relief.
There are times though, where the provider at the door is clearly not the woman in the ad but is pretty damn spicy nonetheless and in many cases those sessions are just fine.
In general though, taking no shit and walking is the only way the B&S will change.