MTN - BEING DISHONEST WITH CLIENTS

HOW YOU ADVERTISE A PARTICULAR PHONE, BUT YOU DON'T HAVE STOCK WHEN I PHONED IN TO UPGRADE MY PHONE THEY TELL ME, THEY ARE BATTLING WITHN STOCK FROM SAMSUNG. SO WHY ADVERTISE THAT SPECIFIC PHONE ???? WHY ARE YOU CHARGING A FEE IF YOU ARE ALLOWING PEOPLE TO UPGRADE EARLY ?