Hello.
user
Hello. How can I  help you?
assistant
I want to change my existing reservation, due to my exams has been postponed. Can you please assist me to change it?
user
Sure, may I know your name please?
assistant
My name is Kimberly Turner.
user
I am sorry no reservation found on your name.
assistant
Ok, no problem. Thanks for your service.
user
Thank you for choosing us.
assistant