Hello, myself William Hill.
user
Hello, how may I assist you?
assistant
I want to change my departure day in my existing reservation, could you mind help me in changing?
user
Sure, please wait for a moment.
assistant
Ok, take your time.
user
Sorry, there is no reservation found on your name in our database to change.
assistant
It's ok, thank you for the information.
user
You are welcome.
assistant