Hello, I am John Taylor.
user
Hello. How can I aid you?
assistant
My exam scheduled has been postponed, so I want to change my existing reservation. Can you please help me with that?
user
Ok, please wait.
assistant
Ok.
user
 Sorry, no reservation was found on your name.
assistant
Ok, no issues. Thanks for your service.
user
 Thank you  for availing us.
assistant