If you had an appointment scheduled with a provider that is canceled that day, and you really want to see someone that day, what is the best avenue to take? I will of course do my research and know the most compatible ladies for me by getting VIP membership.  I know many ladies do not do last minute appointments and I understand that, but some do I'm sure.  On one hand, I don't want to wait around for one of them to return my email, text, or phone call.  But on the other hand, I don't want to send a dozen or more emails or texts to different ladies either.  I could just start calling and going with the first one who picks up.   In a situation like this, is it better to punt and set something up that is not last minute?

It has happened to me a few times both here in town and when I've been traveling. I guess it depends a bit on where you are.  Boston has several good agencies as does Miami (where I travel for work on occasion) I've had less agency luck in places like Philly and Chicago but you never know until you start looking.

....Eros, as well as who is logged on at P411.   You might be pleasantly surprised!

You may find an independent provider available last minute but maybe not. You've already stated the issues with that. Agencies would likely be able to accommodate you. Find a reputable one, check out the reviews of the ladies and call them up and go with it. You will need to be screened. My experience with that is it's fairly quick and easy with many of them. YMMV  applies there too though.

Also, you can try TER "chat with a provider" there may be one in your area online.  
finally, like others have said you can try an agency,

ditto..worked for me..just give her some leeway..