Letsbuy.com — Product now delivered even after 3 weeks

I am yet another unfortunate customer of letsbuy.com. I have ordered a Samsung Star II Duos for my sister on November 17th. The promised delivery date was 3-5 days. When I called them after 5 days they told me that the product is currently out of stock and the delivery will be made within 1 week. But after a week when I called them they told me that the product will be dispatched within 48 hours, I waited but after 48 hours they told me to wait another 48 hours. Now after 3 days when I called them I was told that they can't guarantee nothing, of the delivery time.
How could these stupid online company stay in business with this an irresponsible crew.
If you check the attached image you can see the details.
My Phone number is [protected]