Zylis knives and angry birds

Why does Spar bother having these so called promotions (You still paying for it) like the angry birds and now the knives and everytime you go to buy the knife or angry birds a person has to hear sorry we out of stock but its not our fault its head office. Really as a consumer I don't care whos fault it is sort it out spar bothasig has been out of stock now for a week REALLY this seems like just a way to get us inside the spar to purchase more goods. I think leave the promotions as your head office has no idea how to run it and they giving all the Franchisees a bad name.