passing bucks will never do business with them

I bought a cellphone on the 1 May 2019 at Cash crusader Midrand, when I got home I charged the phone and it got full, I realised it has an issue because the battery wouldn't last so i decided to buy a new battery to my surprise still the same issue and when charging it the phone would be hot, on Saturday I then went back to CC Midrand , 1 of the sales lady even said so herself that the phone has a motherboard issue ,it looks like the store was aware of this issue ,but i was never advised as client ,I was then told I can't have my money back or exchange which i find it not totally fair to the consumers,