Hello.
Hello, how may I support you?
 I made a reservation earlier in the wrong date unknowingly so, I want to change my existing reservation.
Sure, may I know your good name?
Sure, my name is Melissa Green.
Please wait for a minute, I will revert to you with current position.
Sure.
There is no reservation found with your name.
No problem, thanks for your service.
Thank you for availing us.