How to cancel an amazon order that has already shipped

To cancel an order that has already been dispatched: Go to Your Orders. Select the Request cancellation option and proceed further. The item(s) will be returned to us for a refund (if the payment is already made)

For a fee, USPS Package Intercept^® lets the sender or recipient stop delivery or redirect a package, letter, or flat that is not out for delivery or already delivered. Most domestic mailings with a tracking or extra services barcode are eligible for Package Intercept. You can only request a Package Intercept online.