Re-scheduling appointments between different therapists on different days

When a patient reschedules an appointment to a different day, we are unable to EDIT the existing appointment with a different therapist. The patient has to be scheduled with the same therapist on the new day and then moved over to the new therapist, and the original appointment is not removed from the original schedule.

We need the ability to drag and drop the appointment to another day and therapist to change the appointment. We also need the ability to "Edit Appointment" and change any/all information (including NEW THERAPIST) for ease of rescheduling appointment.