Availability of Lumia 640

On 8 August 2015 I requested an upgrade on my contract. The Microsoft Lumia 640 was available for my upgrade but was out of stock. The branch manager at the 4U branch requested an order for the phone and promised to get back to me. I followed this up several times and was told it was on back order. Again, the branch manager never got back to me. I have now been informed that the phone is discontinued. Why has it taken a month and for me to personally go in to the branch to find this out? I demand that Vodacom honours my upgrade request for the Lumia 640, as the request was made when Vodacom still stocked the phone. I also demand that the branch manager is taken to task about following up on my request, nor for his inability to contact me back. I have been fighting for over a month now. I might further add that the Lumia 640 is still advertised on the 4U website. Vodacom, do something about this or I am taking my business elsewhere where I don't mind forking out more money to get what I want.