Bad services

I bought a cell phone from one of the my nearest store last year August 2020. I used the phone for one month then it went blank, I could hear the incoming calls but can't see who's calling and can't answer as the screen was blank. I then took it to the branch and they booked it for a repair. After 3 weeks my phone was back and fine. I used it for few weeks and it continues with the very same problem, I took it back again and asked to see the area manager but the stuff used to tell me of the absence of the area manager. They took it again for the repair, then it came back fine. I used it for a month and it continued with the very same problem, I then went back to the branch and ask for a new cell phone or refund, that's where I found the bad services with a rude stuff member. I then sent an email to the head office, my email was clear enough with every relevant information regarding the matter. Then since the head office disappear, I sent them email again as a follow up and they rep**** asking for branch details and I did resent the details. They disappeared again, I also sent an email again reminding them that I am still waiting for their feedback but I haven't got any response from the head office till today, it's been two months now since I contacted the head office. I am so heart broken as I used to love and prefer their company amongst others.