Hi. I am Steven Campbell.
Hello, how can I guide you for today?
I would like to change my recent  reservation, as my exam is postponed? Can you help me?
Sure, I will help you with that.
Ok.
Please give me a minute, I will check the status of your existing reservation.
Sure.
Sorry, there is no reservation found under your name in our database.
That's ok, thank you.
Thank you for contacting us, have a nice day.