http://resolutioncenter.ebay.ca/
If more than 45 days have passed from purchase, you cannot open a Dispute.
Instead go to the credit card you actually paid with and open a chargeback at the card's 1-800 customer service number. You may have to provide proof of delivery and almost certainly will have to provide proof of mailing.
Cards have deadlines too, so act promply. Have all your dates, payment amounts, currency used, and transaction numbers handy to help the CS rep with your refund.