Telkom samsung A51 faulty

I bought a phone CASH ( samsung a51) on the 7th of may 2020 at telkom n1 city. The phone has been giving me problem not even 5 days later. When I go to telkom I have to stand in a long line just to get in. When I told the lady at the door (after standing in the line outside for over 40 mins TWICE!) The lady tells me I should phone customer service. I've been calling customer service and they not helpful. I mean i spent 6300 for a phone that didnt even take a week to start being faulty. I dont have that type of money to just accept this inferior quality like its nothing.