Hello.
Hello. How may I assist you today?
I want to change an existing reservation, so please help me in changing the reservation.
Sure, I will help you. Please let me know with your name.
Myself Andrew Perez.
Please allow me a minute.
Ok.
 Andrew Perez, I am really sorry to inform you that there is no booking found on your name.
Not an issue. Thank you.
Thank you for understanding. Thank you for reaching us. Have a great time.