Nissan magnite with faulty engine and a bad customer service

My sister bought a brand new Nissan magnite at Nissan Randburg. She only drove it for 3 months then it had an engine failure. Since she's based in limpopo she took the car to Nissan Tzaneen for an assessment, till today she's still waiting for them to conclude an investigation. ..its been over 3 months , worse part is that they not even giving her a courtesy car since ' they are not done with the investigations'. I have been busy contacting Nissan SA but the arrogance of the customer care line is disgusting. Nissan should do better and treat their customers with respect.