Nambu Cast Iron Kettle by Tetu

So I purchased this item because I've been eyeing it for a while, it is completely cast iron but after doing a lot of research, I discovered that this particular kettle was kilned for so long that it would not rust. This kettle is pricey, and it's small, it holds enough water for 2 mugs of tea, and it RUSTS. The little paper it came with was completely in Japanese(?), with no English instructions (and googling won't bring you any instructions either). I have no idea how to "care for it" other than regular washing, rinsing, etc. There are rust spots on the bottom that I have no clue how to remove. Very disappointing for the price.

Ultimately, after much correspondence regarding the new and revised handle for the lid of this very beautiful product, I wish to clear the Seller's name of responsibility for listing, describing with an attached group of photos the kettle which I ordered,which was the original design and won an international award for product design, and then delivering the "new, revised, and updated edition." They have been responsive and agreed to my return request, they have answered all my emails promptly, and the point is in returning this item, the important thing is we have all ended up smiling, with the possible exception of the factory, which is reconsidering their decision, I hope.