The show Wicked at QPAC was forced to displace 40 000 tickets in response to the Brisbane floods. That means 40 000 phone calls to make to patrons who may want to reschedule or may want to get a refund. Let's say it takes an average of 20 minutes to make each of those phone calls, and say they can have people working on it, non-stop, for 8 hours per day, 5 days per week. That's only 120 calls per worker per week.
To get through all the calls in a reasonable time of two weeks, they'd need 334 people working full-time. If you're paying them $20/hour, that's $534 400 just in wages, not counting phone call costs, administration and office rental that you'd obviously need for your brand new 334-strong dedicated call centre. So if they can afford to spend that much on rescheduling tickets, imagine how much they're making by putting on the show.
Mokalus of Borg
PS - There may be fewer than 40 000 people to contact, due to group or pair bookings.
PPS - It's funny that a show about the Wicked Witch of the West was damaged by water...