I bought a phone at ...

I bought a phone at Mr Price and it has factory faulty, it keeps on switching itself off when I take it to the store for the first time they told me they'll fix it they return the phone without giving me report on what was the problem, the phone did the same thing again I took the phone back n they're telling me the same story my question is what is it that they're fixing as this phone has factory problem instead of giving me another phone, I spoke to area manager Sujith he kept on promising to call me back after taking to consultant at store until to date no feedback, he is telling me that they have terms n conditions which was not explained to me.... I'm very annoyed, irritated, frustrated and disappointed with the service I'm getting from Mr Price, can you please assist me with this issue