Hi.
Hello. How can I assist you at this moment?
Owing to an emergency, my live concert got postponed, so I want you to change my existing reservation.
Sure, I am happy to help you with that. Can I have your good name please to check your reservation status?
Sure, Gary Williams here.
Ok, please wait a moment.
Sure.
Sorry Gary Williams, no reservation  has found under your name to change.
Ok, no issues. Thank you for your assistance.
Thank  you for choosing us, have a good day.