You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you at this moment?

USER: I need to cancel my ticket because I am unable to travel due to some personal problems. Can you please help me in cancelling my ticket?

ASSISTANT: Sure, can I know on which name ticket has been booked? Please wait for a moment.

USER: I am Brandon Collins.

ASSISTANT: Ok. Sorry Collins, no ticket is existing on your name.

USER: It's ok, I think my sister already cancelled my ticket.

ASSISTANT: Thank you for reaching us.

USER: Anyway's thank you.