I need help with a refund

So i been using depop since a year now and this time the seller didn’t ship my package and i saw my status saying “we protect” and some other stuff and how i get a full refund on October 9 (yesterday) and yesterday pass no refund deposit in my account yet. i even ask the seller for a refund the day before bc i didn’t wanted it no more and it wasn’t ship yet (he say yes) and today still no refund. so how does this refund thing work???