Samsung Phone faulty from factory

Bought the phone from Samsung Store in East Gate on the 30th July 2017. 30days later the phone was not charging. It went for assessment and found that the changing pin on the phone was fault (could have been a factor fault). It was repaired. On the 10th December 2017 the same problem occur. I feel due to the phone been faulty, it should be replaced. The store manager Simphiwe ********** 157 says he is not sure and will come back to me. I need a phone because I am flying out of the country in a few days. Samsung it not giving the service I require. I require I phone replaced or my money back