21k laptop broken, sent in, never fixed

End of April 2014, I purchased a Toshiba Qosmio laptop from Computer Mania Canal Walk for R21,000. In addition to the 2 year warranty, I purchased an additional years warranty as well. 9 months later, my laptop starts switching off at random moments and eventually dies completely. I turn it into Computer Mania. 3 weeks later I get my laptop back after they replaced the video board. It works for 1 day, then dies again. I send it away for repairs again. Another 3 weeks go by, and I get the laptop back. They replaced the mother board. I use my laptop for 1 day and again, it dies. This time, I go directly to their repair center in Montague gardens and hand it in for repairs there. Another 2 weeks pass and they eventually claim it's the video board again, the previous one they used is faulty, and they must import one from Dubai with overnight shipping. I wait 4 days only to get told the video board didn't arrive. At this point, I've been without a laptop for 2 and a half months