Hello.
user
Hello. How can I aid you today?
assistant
I want to change my reservation, which was done three days ago. Can you help me?
user
Sure,  I am gleeful to help you with that. May I know your name please?
assistant
My name is Angela Smith.
user
Please wait for a while.
assistant
Sure.
user
Thank you for waiting, but I am very sorry to say that, there is no active reservation found on your name in our reservation list to change it.
assistant
Ok, thank you for the information.
user
Thank you for reaching us, have a nice day.
assistant