Plans change. This page says when an order can still be cancelled, how to do it, and what happens to a payment you have made.
Cancelling it yourself
An order that has not been paid for yet — one to be paid on delivery, for instance — can be cancelled from its page in your account for as long as it is still pending, that is, until it has been confirmed.
Asking us to cancel
An order you have already paid for, or one that has been confirmed and is being prepared, is cancelled by writing to us through the Contact page with the order's number. If it has not yet been handed to the delivery partner, we cancel it. An order with products from several sellers is one order for each seller, and each can be cancelled on its own.
Once it is on its way
An order that has been shipped can no longer be cancelled. You may decline the parcel when it arrives, or return the product under our Return policy.
When we cancel an order
We may have to cancel an order ourselves: when a product turns out to be out of stock, when we cannot deliver to the address, when a payment does not arrive or cannot be verified, or when a price was plainly wrong. You are told as soon as we know.
Your money
Whatever you paid for a cancelled order is paid back in full, as our Refund policy describes. Nothing is charged for cancelling.