Hi.
Hello, how can I help you today?
Owing to an emergency, my planned trip to Navajo  adventure with friends got postponed. So I want you to change my existing reservation.
Sure, kindly mention your name.
Sure, I have a recent reservation with name Anna Hall.
Please wait a moment.
Sure.
Sorry to inform, no reservation found with your name.
Ok, not an issue.
Thanks for reaching us.