No stock on advertised items

I honestly don't understand why MTN would launch a catalogue advertising all those amazing deals and when you head in store they have no stock nor stock at any other branch either... The catalogue if meant to be valid for the month of February, Today is the 3rd yet... no stock, then why advertise it in the first place if you have no guarantee that you will have stock on the 3rd day of the 28 days your deals will be valid for on devices that has now proofed to be very popular so why not order enough to supply the demand? But on top of that having to walk out an unhappy customer since I wasn't even offered to have the device ordered or no alternative suggestions has been made so why not just cancel my contract?