Rusty Dishwasher

I bought a Hisense dishwasher 13months ago and it is rusting. How can something that is only functional with water running through it have rust?! Worse is being told that the warranty doesnt cover rust, I never knew that this was even a possibilty as I have had a previous make (which didnt rust and worked great btw just wanted a new one after 8 years). If this is the quality that HIISENSE sells I would not recommend any of their products. Fool me once only.