Traumatic experience in Vodacom Kenilworth Centre

I went to a Vodacom store in Kenilworth centre for an IPhone charger. The store manager asked to see my phone and I told I wanted a fast charger and asked how long a fast charger usually takes and he said 30min-1hour. A couple of days later I went because this new charger took 2-3hours to charger. When I got there to inform of my observations the way I was treated was shocking. The store manager came from the back and was very rude saying I was not telling the truth, claiming that he didn’t not see the phone I was using, he did not say 30min to an hour, and telling me if I wanted a faster charger that I would have to pay R300 more. When I asked him why he didn’t tell me there was a faster charger as if I had known I would have gone to Claremont Istore to get a charger as I thought since some Vodacom stores IPhone they would have chargers, when I asked why was he not honest with me from the beginning he then claimed that I was in a hurry and gave me numbers to call claiming it is the head office, that number did not work. This is not fair on us customer and the disrespect and rudeness, totally unacceptable. I write this is a heavy heart because I paid for that charger and even now a week later this very charger that is new I must fight with it to get it to charge my phone. R600 for a charger that is giving me problems after 2weeks. Please help, in a desperate situation.