Bad customer service

I bought a phone on the 25th of September 2024 at pep cell church street and after about 2 days it started reflecting some fine lines on the top right corner of the screen that come n go anytime then today on the 30th of September 2024 I went back to the store to explain to them what was happening with the so they can change it for me.Firstly the store manager(Tshepi) after I explained to her assistants what was the problem with the phone they said she will assist me further because by then the lines where not showing she just left me there and went to the back to sit n have lunch,she was then called and then she said that she can't help me with anything since the phone doesn't show the lines at that time I then asked her to atleast call her area manager maybe there might be a solution she said she can't,I then used my sister's phone to call customer care and also asked her why is she not assisting with the issue or call her area manager and she told the customer service assistant that she has the final say in her store she will not call the area manager who will tell her to change the fone for me which will be stock loss for her,I have never seen such service in a store and even worse for a store manager to waste a customers time and the money I used for airtime and she kept saying she won't call the area manager she has the final say.my question is that does being a manager at pep give one the right to I'll treat a customer?do pep store managers have the final say they can't ask further for advise from their superiors?I'm hoping this email will reach the relent people so I can get assistance before the 7days period is over cos my worry is that should the phone worse in time what must happen then .I can be contacted on *** My Name is Tsholofelo Maranela