Refusing to change malfunctioning appliance/Cellphone

I bought a phone at Pep Cell Central City in Mabopane on the 14th October 2019 as a birthday gift to my father. The phone was a Mobicel R1Plus on prepaid purchase.

The cashier then told me that when I get home I should charge for 2 hours before I could do so and that is what I did. After charging the phone for that period I switched it on. After I the phone was on, I took the manual to read so I may know how the phone operates. The manual showed me how to access the Home Screen, of which I did and the Home Screen was accessible. Then the following instruction was on how to access the main menu, of which when I tried all my attempts were unsuccessful, the phone could not access the Main Menu.

So today, 18 October 2019, I took the phone back to the Pepcell Store for assistance. When I got there I explained the situation to the Pep Cell employee, showed them what the instruction manual said how the phone was supposed to operate and what the phone failed to do regarding its supposed operation. The employee took the phone, tried to access the main menu as the Manual instruction book stated, the employee also failed to do so. It was clear that the phone was malfunctioning or had a technical or program error. The employee the asked other employees to try and they also failed. The matter was brought to their supervisor who also tried but failed, she then took another R1Plus phone to check if it was any different, but it also failed to access the Main Menu.

The Supervisor then told me that is how these phones were manufactured, saying the phone was functioning properly and I should accept the phone as it is and use it. I tried to explain to them that the instruction manual booklet specified how the phone was supposed to operate and this phone was not functioning properly because it could not access the Main Menu as specified on the instruction manual. The supervisor called the Mobicel representative, explained to her, then gave me the phone to speak to the representative. I explained to her that the phone could not access the Main Menu, the rep then instructed me on how to do so, which was exactly the same instruction as the one on the Manual, but the phone failed to open the menu. I then told the rep to explain to the Supervisor, handed the phone back to the supervisor who later after speaking on the phone still told me there was nothing wrong with the phone. They refused to fix the phone's problem, refused to change the phone for me, refused to give me my money back, even after I told them that I can take another phone and pay extra to cover the price of the phone, they still refused and told me that the only option I have was for me to take the very same phone I bought and use it. The Supervisor said she called the area manager who told her not to exchange the phone for me and also not to refund me.

When I refused to take the phone back, they called security officers for me. When the security officers got to the store, they requested I go with them to their office along with the supervisor, so that we do not interrupt the operations of the store, I then agreed to go with them. When I got there, the Supervisor and Security officers kept on suggesting that I take that malfunctioning phone and I refused. Finally the Supervisor told me that she will take the phone, wrap it up, put it in a safe until I come to collect it or the phone stays for a period of 1year in the safe and thereafter they will destroy it, they will not exchange the phone for me and never refund me. When we got back to the store, the time was around 17:45 to 6pm and the store was closed, so I went home. How can I receive value for my money? For I refuse to accept a malfunctioning appliance as I paid full required price for a properly operating cell phone. I feel ******, please help.