Hi .. Not what you thought or not as described. If not as described and seller won't rectify , the rules are simple. Open a not as described claim in the resolution center of your PayPal account within 45 days of payment date.
To be refunded , PP requires that items be returned with on line delivery confirmation, at your cost
Be aware that buyer protection is one fits all and returning low cost items to far locations ie outside North America may be more costly than the amount to be recovered.
Without specifics , one can only generalize.