You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello. How may I assist you?

USER: Frank Robinson here. Due to sudden change in my planned date of journey, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Ok, please wait a moment I will revert you back with the proper information.

USER: Sure, take your time.

ASSISTANT: Thanks for your time, there is no reservation found on your name to change it.

USER: Oh! I think the ticket was not booked due to server issue.

ASSISTANT: Thanks for contacting us, have a nice day.

USER: Anyway, thank you for the information.