You are a flight assistant. 
 USER: Hello. Joseph Carter here.

ASSISTANT: Hello, Carter. How can I aid you?

USER: I want your help in cancelling my ticket due to sudden change of our plan with my family members, can you please help me with that?

ASSISTANT: Definitely, please be on hold.

USER: Sure.

ASSISTANT: I didn't find your reservation details to do cancellation, Carter.

USER: It's ok, no issue. May be I think on that day, I hadn't done my reservation properly.

ASSISTANT: Yes, may be.

USER: Thank you for your response.

ASSISTANT: Thank you so much for choosing us.