Hi.
user
Hello. How can I help you?
assistant
 Due to sudden change in my planned dates, I would like to change my reservation. Can you please help me out with that?
user
Can you please provide the name on which the reservation has been confirmed?
assistant
Sure, my name is Mary Scott.
user
Sorry, there are no reservation found by the name that you have provided.
assistant
No problem, thank you so much.
user
Have a nice day and take care.
assistant