Poor service and treatment by Nissan South Africa

I am disappointed on Nissan south africa on how they handled the case with Their Queenstown Nissan where my father sent his Nissan xtrail to replace the clutch and the flywheel now the car came back with front shaft assembly problems and Engine vibration and they blame an accident that could have happened with the first owner, because we never had an accident before with that vehicle Which is untrue because the vehicle had an road worth test when it was bought and it had two services with them how could they miss that twice and even when the car was taken for the clutch replacement on receiving the vehicle the didn't mention this until my father went for car collection I am also disappointed on Betty from Nissan south africa customer service care on how she handled the matter, she backs Nissan Queenstown based on the picture she claims was sent to her with a Dent on the oil sump saying it causes engine vibrations I asked for the technician report based on case as they the car for inpspection and both Nissan Queenstown and Betty refused to email the report Nissan Queenstown is scaling my dad and Nissan south africa is backing them and investigating the matter