Violation to my Customer rights

I bought a P40 lite which is a dual sim at Vodacom East Rand Mall. They failed to disclose that they configured the phone so that only one sim works. I went back and both Managers Tony and Nagell told me they're not obligated to tell me anything. They were both rude telephonically and also when I went to store. The tech guy named Shaheen saw that they were at fault but threatened by Tony so he ended up not helping me out. I really am disappointed and I'd advise people not to buy from there.