http://resolutioncenter.ebay.ca/
You have 45 days to open a Dispute about an item that has not been received or which does not meet the listed description.
To the second, so don't delay.
The first instruction is to contact the seller, if you have already done this, go on to Step Two.
If more than 45 days have passed you can go to the credit card that you really paid with (Paypal is just a mediator) phone their 1-800 number and ask about a chargeback.
You have 60 days to leave feedback. The most effective feedback is calm and factual.
At the same time you will be asked to leave Detailed Seller Ratings. A pleasant normal transaction gets Five Stars. The lowest Rating is ONE Star.
If a seller's DSRs drop below 4.3 his fees may rise, his placement in Search may drop, his number and value of permitted listings may be restricted or he may be booted off the site.
Or you can phone eBay and chat pointlessly with a bored clerk in the Phillipines.