The first time I won something from Liquidation.com, I paid witht he credit card I had registered with them. Did you pay Liquidation or the person selling? I think all payments go through Liquidation. That way the seller remains completely unknown to the buyer. Liquidation then takes their cut and passes the rest on to the seller.
It does take a little while for Liquidation to ship. You should have received a tracking number. I would call the buyer help number for Liquidation and find out what is happening.