You don't, - unless you paid with a credit card. You only have 45 days to take action, and if it has been 2 months, much as I hate to pass on bad news, at this point ebay/paypal will do nothing to help you. See Section 4 of the following:
http://pages.ebay.ca/help/buy/item-not-received.html
There are only 2 reasons to open a claim, 'Not as Described' and 'Not Received'. When an item does not match the listing description, and the seller is no help at all, the thing to do is open a 'Not as Described' dispute. You will likely be required to send the item back with Delivery Confirmation, entering the DC number in the disupte. Once it is ascertained that the seller has the item back, you get your refund. You must do it within 45 days of having paid for your item.
Did you return it using a Delivery Confirmed service? If you used a credit card for payment, you can call the 1-800 number on the back of the card and ask to do a chargeback. Cards offer longer deadlines, but it varies with the card, so do it now if it is an option. Have all the transaction details including the DC# at hand when you do.
Otherwise, there is nothing for it. Once past the 45 day deadline a seller will do nothing to help you, so apart from the chargeback you will never see any money. If, however, it has not yet been 60 days you can still leave feedback. After 60 days you cannot even do that.
Truly sorry. 😞
