Big Promises, No delivery!!

I am due for an upgrade from Cell C, for the passed few months Cell C has been advertising this lovely contract buy out which comes with a special cell phone of your choice ( I am a cell c customer). Today I went in for my upgrade. I walked into the new cell c store at the Cresta shopping centre and was told to wait for a consultant to help me. I was asked why I was there and said that I came in for my upgrade, a consultant proceeded to ask me what phone I wanted. I told them I wanted an IPhone 6 plus. I was then told that they were out of stock.... I wanted to know when they would be getting stock and all the consultants looked at each other with a mouth full of teeth. No one could answer me or take down my details to let me know when they would be getting stock. Bear in mind that there is a HUGE poster advertising the iPhone 6 plus in this store. I am disappointed with the lack of service and interest in helping your customers. The cell c store is unhelpful and no one could give a damn about helping their customers. I would like to proceed with my upgrade but unfortunately my service provider cannot assist me. I have also received calls from cell c telling me to upgrade my cell.