Hi.
Hello, how may I assist you today?
 I need to change my existing reservation as my exams got postponed, Can you please help me with that?
Sure, may I know your good name?
Gary Evans here.
Ok, please wait for a minute.
Sure.
I have checked in reservation list to change your ticket, but could not find any reservation with your name.
No issue, thanks for the information.
Thank you for opting us.