Poor service from Renault SA

I am having a problem with my car's aircon for a long time now. The car was in and out of the workshop at the Heidelberg dealer. New pump was replaced. The same problem continued. After some time they told me that the heater box of the car is damaged. This part was ordered more than a month ago. According to the Heidelberg dealer they don't get any response or feedback from Renault SA. I have logged several complaints on their web page. With no response from them. this is totally unacceptable as the holiday season is upon us and still is my aircon of the Sandero not fix. Still waiting for the parts. The car is under warranty. So this should get preference over anything else.