You are a flight assistant. 
 USER: Hello, I am Cynthia Jones.

ASSISTANT: Hello, how may I help you today?

USER: I want to change my existing reservation due to heavy rainfall.

ASSISTANT: Sure, please wait a moment let me check and revert to you.

USER: Ok, I will wait.

ASSISTANT: Unfortunately, there is no flight reservation with your given name.

USER: No problem, thank you for your service.

ASSISTANT: Thank you for availing us.