Hello,.
user
Hello, how could I serve you today?
assistant
I am Margaret Lopez. I make a reservation earlier to attend a get together party with my college friends. Due to some issues in college it  got postponed. Can you please change my recent reservation?
user
Sure, please give me a moment.
assistant
Sure.
user
Sorry to inform, there is no reservation found with your given name.
assistant
Ok, no issue. Thank you.
user
Thank you.
assistant