Hi.
Hello. How can I aid you today?
I want to change an existing  reservation due to sudden change in my trip. Can you help me?
Sure, I am here to help you with that. Can you please tell me your name?
Thank you. Elizabeth King.
Please wait a moment, let me check your reservation status.
Ok.
Sorry, no reservation found on your name to change your reservation.
No issue. Thank you.
Thank you for reaching us.