What I would do is either stick with the independents or make sure,when you make that first call to the agency,that you tell them that you want only the girl or girls that you ask for and that if they send someone different than what your asking for,you are not opening the door for them and that they will be wasting their time! But you're still better off sticking with the independent ladies.

I have only dealt with independents to this point, and have not had any problems like what you describe (bait and switch).  So I agree with the other response, focus your attention on well reviewed indies, do your research.

However, I do know of associates who have run into the problem you describe.  They report that they have taken the approach of telling the lady that a mistake was made, they are sorry for the inconvenience and they offered a payment (not the full rate) to compensate her for her time.  This way, other potential problems (like lurking Guido) can be avoided.

...is that when she opens the door for you, you don't have to enter if you don't like what you see.  But as the others have stated, this problem and a whole host of others can be avoided if you stick to well-reviewed ladies.  Now that you've discovered this resource you're on your way.  Good luck.

If you were lied to send her packing and lock your door. Call the police if big Guido shows up.
I have found that reviewer have different ideas about what is beauty on a lady. I had one case where the lady had a substantial number of reviews rating her looks 9+. She showed up and I did not consider her any better than average looking. Of course the looks factor was a downer for me and it showed in my performance, but I lived up to the agreement that I had made with her while booking her.
The moral is that if she has made an agrement with you based upon good faith dealings on each of your side and she turns out not to ring your bells upon showing up, you need to honor the agreement that you made.

.... just my opinion, in the case your referred to (*the agency sending out a completely different girl*) politely tell her she is not the person in the ad and you are not interested. ~Especially in an outcall situation, worse case scenario change hotel rooms~
However, if the woman has reviews and her photos are recent on her site then I just suggest you do better research. (*Or shop online ads when you are not totally turned on & in a desperate mode*)
I have heard numerous stories of men who are just "nice" because they didn't want to offend the woman etc.... as in the case of a completely different woman.... I have always recommended that the client speak up, ask her to leave (*or leave her incall*) just going through with it and leaving her your cash only encourages her behavior. In the situation described out and out deception of goods *LOL*  Play safe & know your provider....  ~kisses Tori