You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Carolyn Clark here.

ASSISTANT: What type of service you are excepting from us?

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 to another date?

ASSISTANT: Sure, I am gleeful to help you.

USER: Thank you.

ASSISTANT: Clark please wait for a moment.

USER: Ok, take your time.

ASSISTANT: Sorry Carolyn, there is no reservation found in our database, I think your previous reservation is not done before.

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

ASSISTANT: Thank you for consulting us.

USER: Welcome.