Begin by checking the booking page sent by STA via e-mail. This page will tell you if your ticket is refundable or not.
Next, contact STA Travel via telephone toll free at 1-800-825-3001. Let the agent know that you would like to cancel your flight.
You will be charged a $100 cancellation fee. If your ticket is refundable, you are eligible for a full or partial refund, less the cancellation fee.