"Is the paypal protection active also for purchase in VC?"
Yes it is, Piupa.
I have had to file a dispute with Paypal over my purchase from Vestiaire Collective.
It takes up to 30 days for them to make a decision.
In your case, I believe Paypal will accept the word of authenticate4u.
But, like I said, it could take up to 30 days.
Of course, after receiving news that you have filed a dispute, Vestiaire can contact you at any time and offer a refund. They could end the whole dispute, but it seems they are choosing to drag it out.
In my case, the issue is not about authenticity but rather the awful condition of the bag.
The seller actually lied on the posting. I have had to send photographs of the item showing the horrible amount of fading as well as photographs showing some kind of polish that was applied to the bag to try to hide the fading.
I also sent them screenshots of the posting in which the seller claimed that there was absolutely no fading. I have heard that VC will remove incriminating posts, so I took the screenshots just in case.
Really, I do not understand why my refund was not immediately granted by VC.
If they had agreed to a refund, I would have probably remained a customer. But they have lost me, a person who buys high end bags about once a month.
It seems their problem should be with a dishonest seller rather than an honest buyer.
I suppose it is because offering a refund would be like admitting that their "quality control" is a joke.