Hello.
Hello, how may I aid you today?
Can you please assist me to cancel the existing reservation?  Because my health is no good so, I can't travel.
Sure, I am here to help you.
Thank you for considering my request.
May I know your good name please?
 I am Joshua Edwards.
There is reservation found as per your name, shall I cancel it?
That's great, please proceed with the ticket cancellation.
Your reservation has been cancelled.
Thank you for your help in cancelling the ticket.
You are welcome.