Advertising a product they don't have in stock

They have been advertising a sound bar (Skyworth) for quite sometimes now. I went to different Ok furniture stores with luck of getting. At Glenmall they even admitted that the product was never in stock they only have what's on display. My question is why advertise something you don't have, something you won't be able to deliver when the willing customer wants to buy? Why ? It's shocking to say the least!!!