Unsatisfied customer

I bought a defy 2 plate at OK furniture in Wynberg and after 2 weeks I was tripping power in my house went back with it to the store and power tripped and they couldn't give me a new one talking about assessment and waiting 21days which in the process of talking to the supervisor named Aisha that it was not favorable she started shouting and told me to use my logic and proceeded to tell me I was wrong .She was very rude and was badmouthing me with the other staff shouting around the whole place