Hello.
Hello, how may I help you?
 I made a reservation earlier in the wrong date unknowingly. So, I want to change my existing reservation. Can you please help me with this?
Sure, can I know your name?
My name is Betty Campbell.
Please wait for a moment to check your details.
Sure, take your time.
Sorry to say, no reservation found on your name.
It's ok, thank you.
Thank you for reaching us.