Hello.
user
Hello, how may I be of your service?
assistant
As my exams were postponed, I need to change my existing reservation. Can you help me with that?
user
May I please know your name?
assistant
I am Anthony Parker.
user
Ok, I will help you. But, I am sorry to inform you that there is no existing reservation available on your name. Sorry for the inconvenience.
assistant
Thanks for assisting  me.
user
Thanks for opting us. Have a good day.
assistant