Advertising without stock

My contract has been due for a renewal since July 2021. I waited as I wanted the iPhone 12 Pro. I went into the store in November to pre book. No one contacted me. This was Ballito Lifestyle. I went back when the phone launched only to be told there is no stock. In their February deals magazine, MTN advertised the iPhone 12 Pro and the added iWatch combo contract. Again I went in , this time to Ballito Junction... no stock of the watch or the phone. So why advertise when you don’t have the product. I was asked to take the ordinary rather bland iPhone mini. I refused. Again my details where given. I was called by a consultant who offered my the pro max. I refused. It’s a huge phone and not practical. It was also far more expensive. I received a call from MTN asking me to upgrade. I explained which package I wanted and was again told there is no stock. In the March magazine MTN again advertises the phone and watch. I received another call from a different consultant explaining that I needed to upgrade. Again I told her what I wanted. No stock. Desperately needing a new phone ( iPhone starts getting slower as newer models are launched) I went into the Tongaat branch. The consultant explained that they do not have stock and she will order. The next day my phone had completely shut down and being in Ballito Junction , I went back out of sheer desperation into the MTN store. The lady explained no stock had arrived since December of the phone that I wanted and they never received watches. She could not tell me when they would receive same , if at all. Whilst speaking to her, another customer came in wanting the iPhone 12 Pro Max. Again no stock. Needing a phone I asked her what was available and she said only the iPhone 12 without the watch. I asked her if I could sign up for both and fetch the watch when it arrived. Nope not possible. Could I come back when both arrived nope. .. impossible to keep a phone aside. So I took the iPhone 12 thinking it would be better to have a phone rather than nothing. I called MTN today and was told that they have stock of both and it could be sent to me. I have had this contract with MTN since the past 18 years with no hiccups. I am so disappointed that I am saddled with something I did not want based on what I was told by the consultant. I have always taken the latest top of the range iPhones but for this. Why does MTN advertise when it doesn’t have stock and why are consultants either telling people that they have no idea when stock will arrive or that they do have it and it can be delivered ? Come on MTN I was taking a contract to the value of R1300 as compared to this 749 one. Please can someone assist.