Hi.
Hello, what kind of help do you want?
I want change an existing reservation due to sudden change in my trip.
Sure, may I know your name?
Can you help me with that? I am Richard White.
Sure, we are here to assist you. Ok, please wait for a moment.
Ok.
Sorry to say, we did not find any reservation to change on your name.
Ok ,  Thank you for your response.
Thanks for picking our service.