Mtn Sandton store number L13B Horror

I once complained about the Mtn Store at Sandton store number L13B. They took my phone to repairs on the 12 August 2019 and I got my phone back on the 07 October 2019 of which I was in a battle with them. Now as my phone returns they actually send my phone to repairs with wrong information, what they said was my phone had a charger problem and that is not true, I told them the phone had camera/images problem as they appear to be some sort of blurry. The manager(David) refused to change the phone to a different brand with the same amount of money. Please advice me what to do because I can't tolerate the kind of service because now am getting an attitude as if I don't know what I want. Hope to get a different model of cell phone.