Way too late for eBay now (The seller would have known that (30 day limit with eBay)

which is why they just messed you around wanting a video rather than tell you up front...perhaps to make themselves look 'helpful'

If you used Paypal, you have 180 days for a dispute, 

No idea why eBay would have given you more time re the video (unless they were not aware of the dates involved) they won't do anything so long after the last arrival date

So sending emails is pointless and you cannot re-open the case that has been closed

Did you use PayPal?