Hello.
Hello. How may I help you?
I want to change my reservation, can  you please help me?
Sure, I can help you and can I know your name please?
My name is Sarah Thompson.
Please wait for a moment.
Sure.
 Thank you for waiting, I have checked in reservation list to change your ticket but could not find any reservation with your name.
Ok, not a problem. Thank you for notifying me.
You are most welcome and thank you for reaching us.