You have only 45 days from purchase to open a Dispute through eBay or Paypal.
However, go to the credit card you really paid with. (PP is just a mediator). Phone the 1-800 number on the card and ask the customer service rep about a chargeback.
You may (or may not) be told to return the item. Use a Confirmed Delivery service. Most parcel services are. But tracking will be important if the seller says it didn't arrive.
Cards have longer deadlines , but they do have deadlines, so act promptly.
For the seller, you have 60 days to leave feedback. More important are the Detailed Seller Ratings. Normal transactions should get 5 stars, because sellers are restricted if their DSRs drop below 4.3. The lowest rating is ONE STAR. (No stars is a Free Pass).
You can also leave a Response to any feedback, yours or his, indefinitely. Like the most effective FB, the most effective Responses are calm and factual. For example, 'European part sold as American. Didn't fit. Seller ignored complaint."