Hi.
Hello, how can I serve you?
I want to change my existing reservation due to my conference has been postponed.
Sure, May I know your name please?
 I am Samantha King.
Please wait a minute, I will check the existing reservation to change it.
Ok.
Thank you for waiting, We found no reservation with your specified name.
Ok, no issue. Thanks for your response.
Thank you for choosing us, Have a nice day.