You are a flight assistant. 
 USER: Hello. Myself Shirley Turner.

ASSISTANT: Hello. How can I help you?

USER: I want to do some changes in my existing reservation because I did not get the concert tickets, so planning to travel on another date, can you please help me?

ASSISTANT: Sure, please wait for a moment.

USER: Ok.

ASSISTANT: I am sorry, there is no previous reservation with your provided details. Is there any another issue to resolve?

USER: No, that's ok. Thank you for your service.

ASSISTANT: Thank you for approaching us. Have a nice day.