I had the same issue with Depop! I already find it annoying that you have to return the item... I bought what was advertised as a Too Faced palette and didn't realise it was a fake until someone messaged me to say they had bought the same palette as me and that they were pretty sure it was a fake (the size of the mirror and of the pans were different). The seller clearly had bought a bunch of fakes online and was trying to sell them. To me, sending the articles back is just enabling that behaviour, as they'll probably just sell them on another platflorm or with another account... I raised an issue with PayPal and Depop and they said I would get my money back as soon as the seller confirms safe receipt of the palette. They also recommended I pay for tracking so the seller can't say that they never received my item so I ended up paying for tracked shipping and never managed to get the postage money back! I'm just glad I was super petty and just ruined the pans with my brush before sending the palette back
I still lost some money, but at least the seller wouldn't have been able to scan anyone one else with that one.