Still waiting for my Headphones I was promised

On the 24 of January 2015, I went and upgraded my phone. With the package deal consisting of a Sony Xperia Z3 Compact phone and I was suppose to get a Sony Headset to the value of R999 with a Topdog voucher, which it states on my receipt as well. The cashier, Roxanne told me it was out of stock and that they will contact me in a weeks time when they arrive at the branch. A week later I phoned and was told the same story, out of stock, will be arriving in a weeks time. The following week I got a call to inform me that the order has arrived, when I went to the branch they had no idea what I was talking about and there were still none in stock. I have phoned on a weekly basis it is now 2 months later and I have still not received my goods nor even a phone call. I would like to know what is happening and I want my goods to be delivered I am paying for the contract.