How can one trust Poshmark authenticate???

Buyers beware of Poshmark's Authentication... The first 5 photos are what the qr code shows from "Authenticate First" that the seller had as backing to prove Authentication of Valentino purse. They are not clear, very blurry. After receiving the purse, I opened a case because the quality of the purse was totally off. I had the authentication of the purse verified 3 times (one being through Poshmark when purchased). I opened a case because the purse screamed dupe. Poshmark ignored my concerns and claimed purse was already verified from the seller through Authenticate First and second by them. The purse has extremely poor quality. I went with "legitgrails" and the purse was deemed fake. I emailed Poshmark, and they said that's not a trusted site and even tried to tell me in the second email that their valentino expert verified the purse's authenticity. What a joke. I proceeded through an approved site they provided me with, and they deemed it counterfeit as well. I just want money returned and sale canceled. If I was knowingly buying a fake purse, that's fine, but this purse was fake and sold as authentic, and Poshmark authentication team approved it. After this, I decided I am done with Poshmark.