iOffer Ioffer Will not assist with getting purchased items or a refund from their seller Oakland CA California

Complaint Details
I placed an order with a seller housed by iOffer back on 06/01/2018. I received a confirmation of the order, as well as an email when my items were allegedly sent. However, there is NO record of the tracking number being in the carriers system. I’ve sent numerous requests to the seller, youyuan258. The seller has stopped responding. iOffer is not taking ANY responsibility for being a marketplace that houses criminals that not only sell counterfeit items, but doesn’t take ownership when the seller is larcenous and is stealing from consumers. There is NO record that the seller ever shipped anything. This is fraudulent.  Now I can’t get ioffer or the crooked seller, youyuan258 to respond.  I I’d a search on legitimate marketplace websites where youyuan258 is selling from and alerted them of the seller.