You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: Patricia Robinson here.

ASSISTANT: How may I guide you today?

USER: Due to sudden health issue, I am not able to travel in a flight on those date that I want to travel. So, I would like to change my reservation. Can you please help me out with that?

ASSISTANT: Sure, I will help you with that.

USER: Thank you.

ASSISTANT: Please wait for a minute, I will get back to you.

USER: Sure, take your time.

ASSISTANT: I am sorry to say that there is no reservation found under your name.

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

ASSISTANT: Thank you for reaching us.

USER: Welcome.