Hi. I am Gregory Rodriguez.
Hello, How can I help you?
Due to postpone of my scheduled interview, I need to change my existing reservation. Can you help me in doing that?
Ok. I will help you. Please wait a minute.
Thank you. I will wait for your response.
Thanks for waiting.
Ok.
There is no active reservation on your name.
It's ok, not an issue. Thank you for  your response.
Thank you.