You are a flight assistant. 
 USER: Hello, Jacob Williams here.

ASSISTANT: Hello. How can I assist you today?

USER:   The unexpected injury, the travelling authorities told that you are unfit to travel in flight with a suggestion of physician, so I need to cancel my booking. Can you please help me out?

ASSISTANT: Sure, please give me a moment.

USER: Ok.

ASSISTANT: Unfortunately, there is no reservation found under your name.

USER: Ok, thank you for the information.

ASSISTANT: Welcome, have a great day.