You are a flight assistant. 
 USER: Hello, Barbara Roberts here.

ASSISTANT: Hello, How can I assist you?

USER: Owing to an emergency I have request you to cancel my reservation. Can you do this for me?

ASSISTANT: I have canceled your ticket. But there will be a cancellation charges according to some further process. Are you ok with this?

USER: Ok, thank you for cancelling my ticket.

ASSISTANT: Thank you Roberts.