Hello.
user
Hello. How can I assist you for today?
assistant
I want to change my existing reservation, because of my postpone of my exam.
user
Ok, may I know your name  please?
assistant
I'm Emma Mitchell here.
user
Sorry for the inconvenience, there is no reservation found on your name.
assistant
Ok, no problem.
user
Thank you for contacting us, have a great day.
assistant
Thank you for your kind information.
user
You are welcome.
assistant