False advertising

On the 5/01 I placed an order for 3 pairs of shoes on the online site. When I checked the progress of my order I saw its still showing 'processing'. I entered into a online chat with an agent called cohut who told me the warehouse is out of stock. I asked why the items was still showing available on the site and the agent said he would investigate. The next day I received a email saying my order was cancelled. After numerous emails eventually asked for the matter to be escalated and to be contacted by a manager. This never happened. On the 15/01 Still needing the shoes I went back on the site to order, I saw that the 'out of stock' shoes was still being advertised and was still showing available and at a lower price than before. I tried ordering again and waited. Today the 17/01 I received an email saying my order was cancelled AGAIN! If this item was out of stock why was it still on the site 10 days later for a cheaper price? I asked the agent, Dalene Randel, but the agent just continued t talk in circles not offering any answers or solutions. I asked numerous times to be called back, this never happened. Are retailers not supposed to sell products at the advertised prices?