Hello, I am Samuel Phillips.
Hello, how may I aid you today?
I want to change my existing reservation due to my interview scheduled got postponed, can you please help me with that?
Sure, we are here to help you. Please hold a moment, let me check your reservation and  let your know.
Sure.
Thank you for your valuable time, unfortunately no reservation found with provided name.
Ok, no issues. Thanks for your information.
Thank you for opting us.