Hello.
user
Hello, how may I assist you?
assistant
Due to my ill health, I couldn't make my trip to Philadelphia. I would like to change  my existing reservation to some other day. Can you help me with this?
user
Sure, I very much glad to help you in this issue. May I know your name to check your previous reservation?
assistant
My previous reservation has done with my name Raymond Allen.
user
Ok, please wait a moment. Let me check the reservation details in our reservation list.
assistant
Sure, take your own time.
user
Really Sorry Allen, no reservation found on your name. I guess something went wrong in your previous reservation.
assistant
Ok, not an issue. May be something went wrong during my previous reservation. Thank you for providing information.
user
Yes. that's the reason, I didn't your reservation in my data base. Thank you for reaching us.
assistant
Welcome.
user