I know it seems frustrating for many people not to get a response on email. Despite my own experiences, I've also tried to setup appointments at AP boutiques around the world using email but with limited success, until recently, I learned that most boutiques and salespeople get hundreds of email requests a day and tons of WhatsApp requests a day.
What has worked better is directly calling the boutique (or best just going to the boutique). Yes it's a little more effort and is not guaranteed, but it has worked much better for me. Also, it helps to create an account online with your entire collection, so they can find your details.
Cheers and good luck,
Peter