First off, just start over. If you're getting people who don't look like pictures, your going to want to try a different approach. There's a ton of good info on finding reputable sex workers and avoiding scams in the self-help center, which I'll link to below.
As to how to deal with this (which happens, though can be minimized if you follow the linked advice) it comes down to cost vs. safety and the situation. The one time it happened to me I just paid, fucked, and moved on, but in retrospect I wish I hadn't.
A very long time ago (before I found TER) I called a craigslist girl with a hot photo from a hotel phone on a business trip. Someone else (different race, hair, age and body type) showed up at my hotel. I was a total newbie and gave her the money, and had bad sex, ending with her smearing her fake tan lotion on my sheets and me putting a pretty stinky condom in the trash. She even said, "that condom kinda smells" to which I responded, "pretty sure it wasn't the condom."
I got myself tested for everything afterward, was miraculously clear, and have never done that again.
Today, I'm 100% sure I'd never end up in that situation, but if by some crazy dumb decision I did, I'd give her the money, send her on her way, and jack off. But that's me. I have plenty of money and zero tolerance for risk and drama, so I'm a bad "community member" on this one.
I would, however, do an alias review or call it out on the scams board, if those options still exist.
So for you? Search better, use the tools available here, see well-reviewed providers, and stay safe. Glad it didn't go worse!
-- Modified on 3/3/2015 5:51:04 PM