EBay allows several ways to correct problems.
The first is to contact the seller, politely explain the problem and have him correct it, either with a refund or a replacement.
The second is to open an Item Not Received dispute. You have only 45 days to do this, which as you say, have passed.
The third is to leave "appropriate" feedback and Detailed Seller Ratings. You have 60 days to do this, which again, have passed.
If the seller left you feedback, you can leave a Response indefinitely.
If you back your Paypal account with a credit card, you can call the card's Customer Service number from the back of your card and start a chargeback. CC's usually have longer deadlines, but act immediately since they are rarely more than 90 days from the original payment. Have all your information (dates, transaction numbers, values, etc.) handy for the CS clerk.
