Hello.
Hello, how can I help you today?
My examination was postponed due to some reasons, so I want to change my travel dates in recent reservation, will you  help me in modifying the ticket?
Can I have your name, please?
My name is Pamela Phillips.
Sorry, there is no reservation found under your name. Thank you for reaching us.
That's fine, thank you for spending your valuable time.
You are welcome.