Hello, I am Mary Brown.
user
Hello, how may I help you today?
assistant
I need to change my existing reservation, as my medical appointment with my doctor got postponed.
user
Sure, I will help you. Please wait a moment.
assistant
Ok.
user
Sorry, there is no reservation found on your given name.
assistant
OK, no issues.
user
Thanks for choosing us.
assistant
Thank you.
user