You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Anthony Hill here.

ASSISTANT: What type of help that you are looking from my side?

USER: Due to sudden health issue, I am not able to travel in a flight on those dates. Can you please help me out with changing of my reservation?

ASSISTANT: Sure, I am oblige to help you in that modification.

USER: Thank you for that.

ASSISTANT: Please wait for a while.

USER: Sure.

ASSISTANT: Thank you for your patience, when I have checked there is no booking reservation that I have found to modify it.

USER: Oh! I think the ticket was not booked properly while I am booking. Anyway, thank you for the information.

ASSISTANT: It's my pleasure and thank you for communicating with us.