Toyota Dealer not interested in safety of customer

I purchased a new Toyota Rave4 in 2013. I took the vehicle back to monument Toyota for he first service and had to replace the front brake pads. Since then I had to replace the front brake pads at every service 15000 km. Despite asking Toyota to investigate why this is happening, nothing was done to resolve the matter. Even Toyota SA says that it is due to normal wear and that they consider the matter closed. I asked Toyota to inform toyota in Japan and ask them to investigate the parts to try and find out why the brake pads only last 10 000 km. Neither toyota Sa or west rand show any interest to resolve the matter. Now I am left to pay for a vehicle which is unsafe to drive