Professionally ignore people with style.

This automated reply confirms I am unavailable, as previously implied by my calendar. I am away from the office for a general and none-of-your-business absence. Bookings, shifts, and customer theatrics will continue without my live commentary. I will respond when I return, which is earlier than some expectations deserve. If this cannot wait, the on-shift manager is your best bet. Thank you for understanding how calendars generally work.