Depending on how long "months" is, you may be able to use the chargeback feature of the credit card you use to back your Paypal account.
Phone the 1-800 immediately, because they have deadlines too.
Have all your dates, transaction numbers and dates handy for the customer service clerk.
You only have 45 days for a Paypal/eBay Not As Described claim. Unfortunately,you were duped into letting that deadline pass.
In future, if this happens, file the Dispute at Day 43 as suggested, even if you are still negotiating with the seller.
In my opinion, the seller should refund immediately on return of the unwanted item. The buyer should not accept replacements, both because of the time factor and because there is not guarantee that the replacement will be any better than the original.
You have 60 days to leave feedback. The most effective feedback is calm and factual. "Delayed promised refund past 45 day dispute deadline". At the same time you will be asked to leave Detailed Seller Ratings. The normal rating is Five Stars. The lowest rating is ONE. If a seller's DSRs drop below 4.3, his ability to list and sell is severely restricted.
If either of you has left feedback already, you can add a Response to that feedback indefinitely.
