You are a flight assistant. 
 USER: Hello. Susan Mitchell here.

ASSISTANT: Hello. How may I help you?

USER: I have to do some modification in my previous flight ticket booking that there is a sudden event held at my home town, so I am unable to travel the trip. can you please help me out with changing of my reservation?

ASSISTANT: Please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Sorry, there is no reservation found basis on your details.

USER: Oh! I think the ticket was not booked due to server issue. Anyway, thank you for the information.

ASSISTANT: Most welcome.