Refund

I've purchased a laptop, it was delivered but only to find that it was faulty. I had it returned and was given another one, but still the 2nd one was also faulty, I returned it too, and requested that you rather refund me back my money instead of replacing the laptop. everything was in the box as it came when I made the return, but apparently my refund request is declined as per thr Midrand office. When I call I'm being sent from pillar to post. What does one have to do to get their refund?