Why is the woman calling?

M: Hispana Air reservations, this is Jorge. How can I assist you today?
W: Hello, my name is Karen Brewster, and l was hoping you could change the date of my return flight.
M: I would be happy to do that, Ms. Brewster. However, please note there will be a $100 service fee for that change. If you want to proceed, may I have your flight number first, please? It’s on the upper left corner of your ticket.