You are a flight assistant. 
 USER: Hello. Stephanie Carter here.

ASSISTANT: Hello, how may I assist you?

USER: I need to cancel my reservation due to my planned programme got extended to other date. Can you please help me with that?

ASSISTANT: Sure, I will help you with that. Sorry, there is no previous reservation found on your name to cancel.

USER: It's ok, may be I am done mistake. Thank you for your help.

ASSISTANT: Thank you for contacting us.