"3 monts ago" ? There is not much you can do.
- 45 days limit for a Paypal dispute for non received item.
- 60 days limit to leave a feedback.
Never accept an offer of "I will send replacement". Request for a refund, and if you still want this item, then buy it again.
Now, the seller is dishonest when telling you that he can't issue a refund; he can always issue refund by going on his Paypal hstory.
If he doesn't want to issue refund, you have no recourses with eBay or Paypal since delays are passed. If you paid with your credit card, you may try to contact the customer service (phone number on the back of your card) to see if they can do a chargeback.