LG QuadWash Dishwasher Rusting Problem

Two months ago, I purchased a QuadWash™ dishwasher from the LG online store, and rust has formed inside it, particularly on the inside of the door and the bottom tray. I first noticed this issue about a month ago and used the machine 3-4 more times to be sure. However, I observed that the rust was gradually increasing. I am using the machine under warranty and with all the documentation. I only used Finish brand detergent and did not use any products or place any dishes in the machine that were not suitable for it. I contacted LG customer service about the problem and sent photos. However, I was told that the rusting was not caused by the machine itself, but by an external source, and that it could have been caused by splashes from unsuitable dishes or salt. I absolutely do not accept this explanation. It is unacceptable for rust to form inside a machine that is claimed to be made of stainless steel. Furthermore, I have been using dishwashers for a long time, and there is no question of user error. My order number is: 74000068184. I cannot use the machine because the inside is rusted, and I do not find the response provided reasonable. I am requesting a refund for the product.