Did you use tracking?
Yes?- Open an Item Not As Described dispute in the Resolution Centre at the bottom of this page. The name of the company is irrelevant. You need your original transaction number.
No? - Paypal and eBay demand proof of delivery to the seller before they will process a refund. Neither the buyer nor the seller is allowed to have both the money and the item. You will not get a refund.
There are also deadlines for opening a dispute, but the first question is tracking.