Sounds like you managed to become a buyer on ebay without noticing or reading all the info about eBay Buyer Protection.
Contact the seller, tell them what happened, they will most likely send you an immediate refund, will probably ask you to send a picture of the package first.
If you are not satisfied with the response from the seller, go to the Resolution Center, you can find it under the Customer Support tab on the top right of most ebay pages and enter a item not as described claim. Be careful, DO NOT ENTER AN ITEM NOT RECEIVED CLAIM since you did receive something, the problem is not that you did not receive your item, the problem is that what you received does not match the item description. If you enter an item not received claim you will not be reimbursed as that is not true, you did receive something and the seller has proof that you did.
Wish my fingers would pay closer attention to what I spell correctly.