Hello.
Hello, How can I best serve you today?
Due to sudden change of my business meeting because of some technical problem, I need to change my reservation so can you help me with that?
Sure, I am here to help you with that, can I know your good name to proceed further?
I am Raymond Edwards.
 I am very sorry to inform you that there is no reservation found under your name in our database. Thank you for choosing us.
No problem, thank you for the information.
Most welcome.