You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I help you today?

USER: I want your help in cancelling my ticket due to sudden change of our plan with my family members. Can you please do it for me?

ASSISTANT: Sure, give me a moment.

USER: Ok.

ASSISTANT: Can I know your name please?

USER: Sure, my name is Stephen Mitchell.

ASSISTANT: Mitchell, there is no reservation found with your details.

USER: It's ok, no problem. Thank you for your information.

ASSISTANT: Most welcome.