Hi.
user
Hello, may I know how best I can help you today?
assistant
I want to change my existing reservation which is done recently due to some problems, can you please help me?
user
 I have checked in reservation list to cancel your ticket, but could not find any reservation with your name.
assistant
Sure, my name is Jack Rodriguez.
user
We hardly tried to find your reservation but, no reservation has been found with your name.
assistant
Ok, that's fine.
user
Thank you.
assistant
Thank you for your service.
user