A quiet about a phone I bought at pep

Hi my name is ruth ,I bought a phone j4core at pep cell at sontonga mall on the 5 of July and I used it for 2weeks and screen just went blink I took it back they told me that they will booked it for repair ,after 3weeks the told me to come fetch my phone and again I only used it for 2weeks again the screen went again took it back again demanding they should give anew phone or they must refund me no one was willing to help I was told to contact the customer care I phone and get hold of the lady by the of motlatsi she told that she is not dealing with queries she sad she will give the area manager my number to call me log assist me with my complain still waiting even no one is willing to help me cause my concern is that how can a new phone gives problem within 2 month I suspect it's a fault trim the factory now they are sending me from pillar to post I need your help with the matter