"told" how?
Go to Paypal's Resolution Centre and open an Item Not Received Dispute. You may be told to contact the seller but you've already done that.
Go on to the next step and escalate.
If the seller does not refund you, Paypal will and then go after him for their money. It will be ... unpleasant for them.
If you can leave feedback do. The most effective feedback is calm and professional. 'No delivery after 3 months. No refund offered.' for example.
If either of you has already left feedback, you can add a Response. The same words would be fine. Calm and factual.
If neither eBay nor Paypal will accept your Dispute, because you may be past their deadlines, go instead to the credit card you actually paid with. (PP is just a useful mediator). Phone the 1-800 customer service number on the back of the card and ask the rep about a chargeback.
Any of the three (eBay, PP, credit card) will have an effect on the seller and on her selling account. But all three have deadlines so act today.