Bosch Dishwasher Rusting Out of Warranty

We bought a Bosch wga142x1tr washing machine in August of 2012, and it has been two years since then. To our surprise, the machine has begun to rust and swell in the corners. Despite having a warranty, we were told that fixing this problem would be expensive. It's perplexing to us how a two-year-old machine could rust. The explanation that it could be due to water or chemicals is illogical; after all, everyone's washing machine is located in the bathroom. Furthermore, they suggested that we extend our warranty, but why should we if they are unwilling to assist us? According to my research, this machine has a history of such problems. It's disheartening that a machine we bought for 4,400 TL two years ago now needs 3,000 TL in repairs. It's infuriating, and I refuse to accept this result. My old machine, which had been in the bathroom for 14 years, had never rusted. It is absurd to believe that water or chemicals are to blame. The fact that the warranty appears to be completely useless adds to the frustration.