It would have helped to tell us WHEN you paid for this.
Delivery or even dispatch isn't instant on eBay. What counts is the latest estimated delivery date stated in the listing. This includes the seller's normal dispatch time and the speed of the delivery service used (remember that weekends are not counted).
As has been said, if it hasn't arrived by the latest estimate you can use eBay's money back guarantee. As delivery times are only estimated and not guaranteed it's usually fair to allow a day or two longer.