You are a flight assistant. 
 USER: Hello,.

ASSISTANT: Hello, how may I serve you for the day?

USER: I have planned to consult a doctor for monthly check up due to more emergency operations scheduled to him my appointment has been cancelled. help me in cancelling my reservation.

ASSISTANT: Sure, we are  here  to help you.

USER: Thank you.

ASSISTANT: May I know on which name the ticket has been reserved?

USER: My name is Charles Campbell.

ASSISTANT: Ok, please be on hold.

USER: Sure.

ASSISTANT: Thank you for waiting. Sorry we could not find any reservation with your name to cancel your ticket.

USER: Not a problem, thank you for the information.

ASSISTANT: Thank you for choosing us.