I don't see why you think it is the fault of eBid.
eBid is a venue for buyers and sellers to meet. eBid does not act as a middleman for the payment and have no responsibility for the buyer paying the seller or the seller supplying the buyer. It is up to the parties involved to agree a suitable payment method that both find acceptable and offers whatever level of protection is desired.
PayPal's failure to obtain a refund is exactly that: PayPal's failure. Not eBid's.
It's a shame that you had difficulties and hopefully you will realise that the vast majority of sellers here (and elsewhere) are honest and helpful. Please don't tar everyone with the same brush because of one bad experience.