Brand new Nissan Magnite Brakes issue and poor support from CMH Nissan Pinetown and Nissan SA

I bought a new Nissan Magnite in February 2022 from CMH Nissan Pinetown. Brakes are making terrible grunting noise especially when driving down a steep slope. This started just after 2 weeks of buying the vehicle. I reported both at CMH Nissan Pinetown and Nissan SA. I received no assistance and no follow up from CMH Nissan to have the issue sorted. I also reported to CMH Nissan management and Nissan SA. No assistance as well from them. This has been dragging for 10 months now. The latest response is that they are testing new type of brakes and they don't know when that process will be concluded. The grunting sound on brakes is getting worse.