JJ REWARDS / SMART SPEAKERS

I PURCHASED AN ITEM ONLINE ADVERTISED ON SMART SPEAKERS ALSO KNOWN AS JJ REWARDS A FEW DAYS LATER WHEN I QUERIED THE DELIVERY I WAS TOLD THAT I WOULD RECEIVE MY PURCHASE ON 29/05/20 BY 5PM. WHICH I DID NOT RECEIVE. I WAS ADVISED AFTER NUMEROUS TELEPHONE CALLS AND EMAILS THAT THEY ARE OUT OF STOCK. HOW DOES A COMPANY ADVERTISE FOR GOODS AND NOT HAVE STOCK BUT THEY KEEP YOUR PAYMENT??? TO DATE I HEARD NOTHING FROM JJ REWARDS. ARE COMPANIES ALLOWED TO TRADE ONLINE AND BASICALLY DEFRAUD PEOPLE???????????