Elbox isn't calling me up and interrupting my dinner pitching a free trip to Zimbabwe. They're celebrating something legitimate. If they want to have a sale for Christmas in July that's their prerogative. If other companies can't compete that's their problem, not Elbox's.
Make their sales pitch illegal and you'll be creating a law that single-handedly criminalizes just about every marketing department in the civilized world. It ain't gonna happen.
Besides, there are bigger problems to be concerned over than a company finding a somewhat strange reason to be offering free shipping. ;-)