Hi.
Hello, how may I aid you?
Can you please change my existing reservation? Because I need to attend to an emergency meeting at other place.
Sure, let me know your good name please.
So, please change my reservation which is reserved under my name Mary Allen.
Ok,  please wait a while.
Ok.
Thank you for your time. Unfortunately there is no reservation found by your name.
Ok, Thanks for sharing the valuable information.
Thank you for availing us.