Supply of faulty products

I’m disappointed with Vodacom for supplying me with a faulty device and won’t take responsibility. I initially purchased an IPhone. About 6 months later, the camera started acting up showing weird colours etc. The phone was then replaced by another, which after a couple months just shut down and never switches on again. When I took it back to Vodacom. They advised me to buy a new one after 2 weeks of being with the repair store. By this time, the replacement phone was out of warranty. I have taken it to numerous repair shops thereafter who advised that they could not understand what was wrong with the phone. Had it not been the case of Vodacom supplying me with a faulty replacement. I would have not experienced this problem. The phone externally is mint condition. I disugusted and will never buy anything from Vodacom again. I’ll continue to let others know of my bad experience.