Bad service

My mom bought a phone in May 2022 at Pep Pimville assisted by Nolwazi Mbatha,the phone had problems from the first day overheating and application not working and we had to take it back. When I got to pep the security was called to explain to me how phones can have these problems and I should have bought one that has large memory.This was surprising the manager then came and she convinced me to buy a memory card and and try using it .I came back I week later and the phone still had the same problem, overheating and application not working,I was then told 7days have passed they need to book it in which the manager did.The phone returned 3weeks after , having the same problem. This time my mom took it back and it was booked in the phone the second time. The phone came back on the 23 June and my mom requested for a refund since the phone has been having the same problems since day one the manager took the phone back and promised to call and refund. Since then and now 27 July nothing has happened we don't have the refund or the any one contacting us