You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: William Green here.

ASSISTANT: How may I assist you today? Yes Green.

USER: AS our plan got cancelled due to the low budget, please help me to cancel my recent reservation.

ASSISTANT: Sure. I did not found any reservation with your name.

USER: That's fine, thank you for your service.

ASSISTANT: It's my pleasure.