Windows Phone (Lumia 550)

I have used Windows Phone and it predecessors for more than 15 years. In my family of FOUR we use THREE Windows Phones and a older Nokia. I want to upgrade my wife's Nokia to a Lumia 550 on Vodacom. But since January when it was advertised for R129-00 / month on uChoose 110, there is no stock available. Now it is advertised for R149-00 / month on the same contract, but still no stock available. Is Microsoft the problem here? Did you ever wonder why you struggle to get market share with Windows Phone? That is because you can't supply. How difficult is it to ship a simple entry level phone? Must I become a dead fish and go with the flow and buy a device with a flawed OS like Android? Get your act together and ensure you have an effective supply chain.