Hi. I am Anna Gonzalez.
user
Hello, how can I help you?
assistant
  I want to change my recent reservation as my joining date got postponed. Can you help me in changing?
user
Sure, I am here to help you. Please stand by.
assistant
OK.
user
Thank you for waiting. Sorry to say no reservation found on your name.
assistant
OK, no issues.
user
Thank you for reaching us, have  a nice day.
assistant
Thank you.
user