Tavcor refuses to uphold vehicle warranty

After a few months and about 10,000 km's of owning my 2014 Polo, I notified Tavcor about the issue I was having with the car where my brakes were shuddering under strange circumstances. Tavcor then informed me that the factory had informed them about inferior product being used at time of manufacturing and replaced the brake disks without any questions. The shuddering continued, then I took the vehicle back, they then replaced the brake pads as well. Roughly 10,000 km's later and the same problem arose with the brakes shuddering, I immediately contacted Tavcor again to bring this to their attention, they then refused to replace the brakes again. This time around they said the factory had changed the warranty on brakes to 10,000 km's (very ironic). I did some research and subsequently came across hundreds of complaints with regards to Polo's and their brake issues, lots of clients made reference the 10,000 km failure point. I contacted Tavcor again and informed them that I would be taking it further as it is clearly an issue of so many people are complaining and the circumstances are pretty much identical. Besides the fact that Tavcor and the factory admitted to inferior products being used at manufacturing. They then replaced the brakes a second time around, after about 15,000 km's the same issue came up again. I contacted Tavcor again, they sent one of the mechanics with me to test drive and assess whether the brakes were in fact shuddering. I was told it is the ABS that was causing a shudder, which is absolute *******, as the brakes often shudder under low speed conditions. The fact that Tavcor replaced the brakes twice and confirmed that inferior products were used at manufacturing. The service has been shocking and I have brought this up with their quality control and survey service with no response or feedback whatsoever. I will not rest until this issue has been resolved.