Even when a seller is cooperating, it is wise to open that Dispute within 43 days.
At this point, your only possible recourse is to open a chargeback with the Customer Service of the credit card you used to back that PP account. Even there you may be too late.
If either you or the seller left any feedback, you can add a Response to it indefinitely. The most effective Responses, like the most effective feedback are calm and factual.