Sometimes they just get out of the biz, when was her last review ?

Please abort that thought and move along.  For whatever reason she doesn't want to see you. Just let it be.

and ended up over-booking, and is too embarrassed to come out and admit it to you.

 
Either that, or you lost a face-off with someone else she'd rather see, probably because they are paying more.

 
If I were you, I'd write her off an find others who are more dependable, but if you have an insatiable jones for her, then send her a brief friendly text saying that you hope you can still see her someday, and hope for the best.

Lick your wounds and stroke your ego and move on. There are hundreds of fantastic women here and elsewhere to be found. Twitter is an amazing resource and I might get censored for saying that but it's a fact. As well as other sites.  

I used to put all my eggs in the TER basket and it's serve me unbelievably well over the (15) years. Now I have two baskets. I guess 2 head is better than 1 👅

There are several women I've seen more than once,  
and had an amazing time more than once and they just fell off the radar and never responded back. Sure, I'm disappointed, who doesn't like a fantastic time with someone that they clicked with, but maybe I have a shelf life and maybe they have a shelf life.  

But rather than beat myself up and try to figure it out why, or pester them for an answer, its better to move on in the sage words of Mr Fisher

And, in the infamous words of Mary Kay, No? Next !!!

Most likely drugs or alcohol or overbooking, or she made her $$ and was going out with friends or pimp/boyfriend. One thing I've learned from 25 years in the game is always have a plan B.

Although her behavior sounds extremely unprofessional, and I myself always try to be the opposite of everything you've just described, there are occasions when I do just fuck up. We get so inundated with e-mails and texts and calls that sometimes things can get totally overwhelming and you drop a ball. However, in this industry, the tendency on the part of the client is to overanalyze the situation because it's true, it could signify something unsavory that you don't want to get involved in. But if a provider does seem to have the best intentions and is genuinely sorry for the mix up, please give her a break. It's possible she just isn't responding because she's embarrassed. I'd give it one more try then move on.

Good luck! Also, the buffet is plentiful, so if it doesn't work out, feel free to post an "ISO" laying out your preferences in a respectful way, and you might be delighted by what you find.

--Ernestine