You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I help you?

USER: Rebecca Perez here. Due to sudden postponement of my journey plan, so I would like to change my reservation. Can you please help me out?

ASSISTANT: Sure, I will help you.

USER: Thank you.

ASSISTANT: Sorry, there is no reservation with your name to change further.

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

ASSISTANT: Thank you for choosing us, have a great day.