You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello.

USER: Charles Hall here.

ASSISTANT: How may I assist you?

USER: Due to heavy rainfall, my art exhibition is postponed. So, can you cancel my ticket?

ASSISTANT: Sure, please wait for a moment to check your details. Sorry, there is no reservation found on your name.

USER: It's ok no problem.

ASSISTANT: Thank you for choosing us, have a nice day.

USER: Thank you for your information.