Hi.
Hello, how may I help you today?
I need to change my existing reservation as my plan to meet my brother got postponed.
Sure, can I have your name to proceed further?
My name is Kathleen Martin.
Ok, please wait fo a while, let me check your reservation and get back to  you.
Sure.
Thanks for your valuable time, sorry unfortunately no reservation found with your name.
Thank you for your response.
Thanks for your interest, have a great day ahead.