There are a lot of honest sellers and buyers there (I consider myself one of them) but if anything goes wrong, Vestiaire will do nothing to help, they will spam you with auto replies

Indeed, there are a lot of honest sellers but when something does goes wrong, they will definitely not help you.
The customer service only works via chat and they just spam you with an auto reply "there is nothing we can do to help you".
But it seems like a policy, Vestiaire know most people will just accept their defeat and only a handful will fight for their rights as a consumer.

I know I'm not happy with them. I bought a pair of shoes from the actual designer's store in Chicago and they decided my shoes were not authentic and I would have to pay to have them returned to me. Basically they stole my shoes... I think they are a scam. I'll believe the actual store over this site... I wonder who staffs their "authentication" department.