You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello. What help that you are expecting from my side?

USER: As my exams got postponed I want to change my reservation, can you help me with that?

ASSISTANT: Sure, our agency can help you with flight ticket change process with free of cost with out any charge.

USER: Ok.

ASSISTANT: Can I know your name for checking your previous booking?

USER: Samantha Miller here.

ASSISTANT: Let me check with your details in our portal, please allow me a moment.

USER: Sure, you can have a time.

ASSISTANT: Thank you for being on hold, I have checked based on your request and I am unable to find your ticket reservation in our data base to change it.

USER: Ok, no problem. Thank you for checking.

ASSISTANT: My work it to help you and thank you for approaching us.