how do you handle a situation such as when you show up and the girl at the door isn't the girl in the ad?

It has happened to me and I walked.

If the provider lies to get you there. What are the chances of her doing what she advertises for

If it aint "Ruby" when she opens the door, Run like hell and let us know!

If it's in a hotel it's easy to walk away because she doesn't want to attract attention. If it's at her residence then run. I've been sworn at but that's all.

I've received follow-up calls twice after I walked away from a B&S.  One time the tgirl was pretending there was a misunderstanding and her friend opened the door.  Another time I was toothlessly threatened (by phone)...I just turned the phone off.  

Ok, so this happened to me...traveling for business to a hotel in a European capital.  Called a Russian girl (not TS) who showed up to my hotel two hours late, total B&S, fat, ugly, and with a pimp.  Unfortunately for me I'm waiting in the empty lobby, the girl starts lighting up my phone and realize who she came to meet...I slipped up a guests-only elevator (key-card access required), they chased me and left a few threatening messages.  It was very cinematic, this menacing pimp's fingers just missing the door-catch before the magnetic security-lock was engaged.  And it was a glass door, so he watched me cruise away to safety.  

I think they waited for an hour, maybe two, before moving on to the next sucker.   I waged my war of attrition inside a bottle of room-service wine.  I must admit the whole thing was kind of thrilling, but being chased through my hotel lobby was also traumatic enough I swore off outcalls on business trips.

Ok, last B&S story.  

Saw this 'hot TS duo' advertising on CL a few years back, downtown Manhattan.  I get to the door, it's one barely passable, chubby Asian C/D, no duo and nothing like the pics.  But I was a little tipsy, a lot horny, so I decided to get on the massage table for a handjob.  I'll be damned, the CD couldn't even give a decent handy.  Five minutes later I got dressed, said "sorry, you just aren't my type", and left $60 or $80 for the trouble.  Provider was non-confrontational, smiled and said "come see me again" (yeah, right)...all in all pretty painless.  

what about taking a camera pic of the photo ad she's posting on your camera phone and taking it with you to the door when you meet her in person? If she insisted that she is the person of the ad after you've ask,then you can whip out the camera pic and show her.

if she still is quite insisted, then you will have to tell her she is not your type, then excuse yourself to the exit of the door.
if i didn't have a camera-phone then i could always print out the photo ad on paper, then take it with me to show her if i needed to.
if you don't have camera phone pic or print-out
for in person proof,then i'd say i was sick and have to cancel,then hit the door. Seee Ya!