Faulty iPhone 15

I ordered iPhone 15 online as part of my contract upgrade last year, the phone arrived in October 2023. After 2 weeks the phone started showing a blank screen, and then coming back on after an hour or so. Then in March, I went to give birth via C-Section, a few days after the phone screen went blank again; and wouldn't come back on even after a few days, I couldn't leave my house so I left it like that. It came back on after two weeks worked for 2-3 days then went blank again. It remained blank for a few weeks then came back on. I then took it to Mall of Africa where they claimed to have sent it for repairs, after 5 days I was alerted that the phone had been fixed and that I should come and pick it up. When I fetched it on Monday(18:45, 08 July), I was assured that the phone had been fixed and that it'll never give me problems again. On 9 July 2024, the screen went blank again, then I filed a complaint on Hellopeter. A Vodacom customer service agent called me and informed me that the phone wasn’t fixed and that I should send it to the nearest Vodacom shop. I then took the phone to Vodacom Centurion as per my discussion with the customer service agent. I dropped the phone on 15 July, and it was booked for a service on 16 July. On 23 July at 09:30, I received a call that my phone had been fixed and that I should go and pick it up. Shortly after I received the message, I received a call from Vodacom Centurion informing me that they had received the phone, but the phone screen was still blank despite repairs saying they had fixed it, then they informed me that they had to book the phone again.

It seems like there's a serious issue with the phone, and no one is willing to address it. I can't continue paying monthly for a phone I don't use. I have been going back and forth with Vodacom trying to get my phone fixed since the 05th of July, yet there’s no outcome.