Search by treatment and city. See the times that are free, and book.
No messages, no waiting for someone to pick up the phone.
Try "massage" in Makati or "manicure" in Cebu, and see who offers it there.
Choose a staff member, or pick "Any available". Then pick a time and book. No waiting for a reply.
Can't make it? Reschedule or cancel from your account. No need to message the salon.