Rusted Dishwasher Racks

I bought a Hisense Dishwasher in May 2022 via Takealot. At first, it was delivered damaged and another machine was sent. After about a year, both the top and bottom racks started showing signs of rust. The rust has become so bad now that its disintegrating into the machine, now becoming a harmful health risk. The warranty booklet states 4 years of cover but Hisense state that they cannot assist because rust damage is only covered for 6 months. Their solution is for me to purchase replacements for around R2000 - which are currently out of stock and will also probably rust in about a year. My mother has used the same dishwasher for most of my living life with NO rust problems whatsoever. I've never heard of this before and am extremely disappointed. How can a dishwasher be made in such a way that its components start rusting within a year??? I paid a pretty penny for this dishwasher - it wasn't a cheap machine to start with and I definitely wasn't planning on paying R2k a year to keep it running. I will never recommend Hisense as a brand of appliances - in fact, I know now to warn people against Hisense at every opportunity I get.