You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello, how may I assist you for today?

USER: I have planned and reserved a flight ticket for round trip due to some health issues I can not  start my journey.So can you please help me in cancellation of my ticket?

ASSISTANT: Sure, could you please provide your name to check the details of your reservation?

USER: I have reserved my ticket in the name of Gray Campbell.

ASSISTANT: Ok, please wait a moment.

USER: Ok.

ASSISTANT: Sorry to say, no details were found in my database regarding your reservation.

USER: Ok, fine thank you for your information.

ASSISTANT: Thank you for contacting us. Have a nice day.