False advertising! Horrible service!!

I am livid! I have been a customer of MTN for nearly 5 years now and have 2 contracts with them. I processed an upgrade for one of my contracts to a iPhone 7 plus. I have not had any communication from them for more than 7 days until I called them today and the lady told me they dont have stock and "probably won't have for a long time"/ She was not helpful, there was no willingness to assist in any way basically did not care @ all! How can you advertise a device if you dont have it in stock "and probably wont have for a long time"?????