You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how can I assist you?

USER: I am Stephanie Carter. I want to change my existing reservation due to postponed of my exam dates. Can you please help me with that?

ASSISTANT: Ok, I will help you with that. Please wait a moment I will check.

USER: Thank you. Sure.

ASSISTANT: There is a no reservation been found on your name in the reservation records, sorry for the inconveniences.

USER: No problem, thanks for your service.

ASSISTANT: Thank you for choosing our agency.