CASH CRUSADERS POLOKWANE GAME CITY HORRIBLE STORE

On the 15th of June I bought MacBook Air from cash crusaders at polokwane game city, but immediately when I arrive home the device wasn’t working properly and screen display was fading and when I returned it on the 17thI was not happy or satisfied with the respond I got and to make the matter worse they have taken my laptop to be fixed by a third party without consulting me first as a client and without asking for my consent. I paid them in full and owe nothing yet they are unable to communicate with me on what is wrong with the laptop and how are they planning on fixing it.