You are a flight assistant. 
 USER: Hello.

ASSISTANT: Hello.

USER: I am Sandra Martinez.

ASSISTANT: How may I assist you for today?

USER: I need to cancel my previous reservation due to my planned trip got cancelled due to some other important work. So please help me with cancelling my reservation.

ASSISTANT: Yes, I can help you. Give me a moment.

USER: Thank you for accepting my request. I will wait for your response.

ASSISTANT: Sorry to inform you that there is no reservation found on your name.

USER: Oh! It may not be booked duet to server issue.

ASSISTANT: Thank you for contacting us.

USER: Anyway, thank you for your valuable time.