Faulty Macbook Pro

I purchased a Macbook Pro from the Eastgate store in January 2017. Not a week after the purchase, the laptop refused to switch on and had to be taken to the store for repairs. I had to book it in, whereby it took a week before it was replaced. In May 2017, the Macbook again refused to switch on, whereby it was booked in again for repairs. I complained to the store Manager, Yuvee, who refused to exchange the laptop, citing the CPA in defense. I proclaimed that I am purchasing a premium product, and should not have such a bad experience with the product. He promised to exchange if this problem occurred again. The same problem was experienced again in October 2017. I went back to the store and asked to have the product now exchanged as it is clear that the product experience was not satisfactory. The store manager changed and the new manager refused to honor this agreement. I then went to a customer service manager at the "Core Group", the official importer of Apple Products. They refused to assist with the exchange, again citing CPA and other laws in defense. I retorted, that being a premium product, I should not have such a negative experience. I am extremely furious with my experiecne with the iStore and their attitude toward my problem.