Online team and call center useless

Myself and my brother saw the IPhone 6s Plus deals for R299 pm and was immediately interested. It show stock available so we place immediately our order. We got communication for the Vodacom team of our order and that a call center agent will contact us but they did not. We had to contact them just to find out they are out of stock. But what I don’t understand is the deal is still being advertised online and can still be order. I’m disappointed in the service and as a loyal Vodacom customer for years this is not how I would like to be treated. I would like this matter to be resolved by me receiving my iPhone and my contract. And if there is truth no stock a alternative (iPhone) should be offered at the same price. Vodacom is misleading