Buyer files INAD; I offer return and send label; buyer CANCELS return and submits chargeback...next steps?

I sold a collector's game console. It had full photos showing the unopened console. Just said that it's so and so brand. Did NOT state that it was the European version (which plays the same games as the US version but has slightly different packaging). This would have been evident by the photos that were posted. There was very little text in my listing other than "look at the photos and the UPS before you buy." Never said this was the US or European version of the console, so didn't make any claims one way or the other, esp. since I figured it didn't matter since it played all the games anyway....

Buyer submits an INAD. I realize that I have no choice but to offer a return and then dispute the return if the item received is not the same item I sent out.

Next, the buyer apparently closes the return and then files a chargeback.

What's the next step? Item was $500+. Buyer is in FL and I'm in NY. I will file a police report w/ the local station. Do I file one w/ FL police also? How best to respond to eBay? I assume I'll make a buyer report, but what are the next steps for my case?

Happy to pursue this w/ my lawyer who I have on retainer to handle other business matters. Next steps at this point? I purposefully sent the item via USPS, so I don't know if I can get the USPIS invovled. The return label was offered through USPS, but the seller didn't return the item. I do have videos showing me wrapping the item and tagging it with security tape and wrapping the package in security tape and then mailing the item at the post office w/ the weight of the package on the scale.