Awaiting a takealot's competitor

a Few months ago my wife purchased a milex airfryer oven from takelot after her mother had recommended it, albeit, not having that long. The oven worked fairly well apart from the rust that started forming in the my mother inlaws oven, she then returned the item and was fully refunded. We started monitoring ours and rust eventually started forming. We then returned the item (still under warranty) for inspection, the response from them is that the oven has sea air damage and they will not refund. The warranty does not hold that stipulation and there are many reviews reporting rust inside the oven. Living close to the ocean, I've seen sea air corrosion. I've never in all my years seen sea air corrosion bypass outer metal and start corroding the interior first. They still refuse to give us a refund or offer any alterative relief.