Upgrade of cell phone

Please can Vodacom explain their non existent service....yet again! I have contacted them a couple of times over the last month or two to confirm that I have a premature upgrade. Last week this was confirmed for me once again and I checked that I would be able to go anywhere for an upgrade. I went to the iStore on Sandton Drive yesterday afternoon where the consultant logged onto the Vodacom site and was told there wasn't a premature upgrade for my contract. I then called Vodacom again and was also told there wasn't an upgrade for me. I need an explanation of how this happens, that I am told on numerous occasions and by various different people that I qualify for a premature upgrade and the following week when I go to do my upgrade get told that there isn't one. This is completely unacceptable and is shocking customer service!!!