Automated email message

We've noticed the message (attached as a photo) that appears when a patient tries to reschedule an appointment after the rescheduling deadline.

In other words, if a patient wants to reschedule their appointment less than 3 hours in advance, they aren't allowed to because of our policy. However, they receive this message asking them to contact us to arrange the appointment, which is what we want to avoid.

How can we change this message to say something like, "We look forward to seeing you at your scheduled time" or "We look forward to your next appointment"?