Hello, I am David Thomas.
Hello, how may I assist you at this moment?
As my manager did not approve my leave, I would like to change my existing reservation.
Sure, please wait for a moment. I will check the details and let you know.
Ok, take your time.
Sorry for inconvenience, there is no ticket existing on your name.
That's ok, thank you.
You are welcome. Thank you for reaching us.