Hello.
Hello, how may I aid you today?
I would like to change my existing reservation, due to examination schedule postponed. Can you please help me?
Sure, may I know your name?
My name is Matthew Gonzalez.
Wait a minute, let me check you reservation and revert you.
Sure, take your own time.
Sorry,  we could not find any reservation on your name.
That's ok, thank you for your information.
Thank you for reaching us.