Hello.
Hello. How may I guide you?
Can you please help me in changing my existing reservation?
Sure, I can help you to change the ticket details. Can you please  confirm me your name to check the ticket status?
My previous reservation has done with my name Kenneth Phillips.
Ok, please give me a minute.
Sure.
Sorry for the inconvenience, there is no active reservation found with your name to change.
Ok, not an issue. Thank you for providing information.
You are welcome. Thank you for approaching us.