It's sadly true that an online selling platform can be home to sellers of fake items, not just Pandora.
Good to hear you say those sellers are now classed as ' unregistered sellers' that means they have been banned from selling from eBay, no doubt from a show of too many returns for these fake items.
With over 7 billion listings on at any one time, it's not possible for eBay to check the authenticity of items, they do work on a disproportionate number of returns opened by buyers, then they can act with selling sanctions even bans as your seller deservedly received.
Buyers thankfully have eBay's 30 day MBG Money Back Guarantee to protect them so they are guaranteed a full refund, if they are unfortunate in receiving an item not as described.
@gmesidar