Hello.
user
Hello, how may I assist you today?
assistant
I am Richard Adams want to change my reservation  due to prepone of my business meeting.
user
Sure, please wait a moment, let me check your reservation and let you know.
assistant
 Ok.
user
Thanks for your time, sorry, unfortunately no reservation found with provided name.
assistant
Thank you for your information.
user
Thanks for opting us, have a great day ahead.
assistant