Hello,.
user
Hello, May I know your good name?
assistant
I want to change my existing reservation which is with the name William Turner, as my office conference got postponed.
user
Ok, please wait  a moment I will check and revert you.
assistant
Ok, sure.
user
Unfortunately there is no reservation found on your name.
assistant
Ok, no problem. Thank you for the information.
user
Thank you for opting us.
assistant