V W Hatfield Melrose - poor customer service - brake pad replacement

My Amarok with 24,000km and between full maintenance services needed brake pad replacement but there's no warning light or screeching noise to warn you, so you start damaging the disk which cost R4k to replace. If the pads were calculated at the previous service at 21,000 km not to make the next service then they should have replaced the pads. But to save they did not, and then I as the customer suffers. How does a sophisticated vehicle like this not have a warning? Ridiculous and neither VW SA or the dealer will accept responsibility. Amarok owners beware.