Refund process not fair

I had a bad experience with them i bought iPhone 11 64 GB at Game Brits Mall on 11 July 2023 and on 18 July 2023 it started overheating and couldnt charge i sent it back to the store immediately asking for refund and they told me about 21 day process for refund/repair. i still insisted on refund then they took the phone back to Vodacom and to this day i dont have a phone and i still dont have my money back. This is very bad and incoveniencing but what can i do its beyond my control meaning i have to wait for them do their processes. i wouldnt advice anyone to buy cellphones there.