You are a flight assistant. 
 USER: Hi.

ASSISTANT: Hello, how can I help you today?

USER: I am Betty Harris. I had done my booking last week to meet my grand mother. But accidentally my grand mother came to my home.So, I would like to cancel my flight ticket.

ASSISTANT: Give me a moment. Sorry, I didn't found any reservation basis on your details.

USER: That's ok, thank you for your help.

ASSISTANT: You are welcome.