Dyson Humidify+Cool Water Tank Error Recurred - Warranty Denied

I purchased a Dyson Purifier Humidify+Cool from Dyson Turkey through their official website, and I am using the device in Ankara, Turkey. Since December 5, the device has been completely non-functional and constantly displays a “water tank not inserted” warning, which prevents it from working at all. I had the same problem before and, while the product was still under warranty, the same part, the water pump, was replaced twice. The device is only in its fourth year, and I would like to emphasize that I use it only during the summer months and rather infrequently. Despite this light usage, the same malfunction has recurred. When the problem appeared again, I contacted Dyson on December 5. This time I was informed that it was a user error and, since the warranty had expired, I would be charged for the repair. I was also told that not only the water pump but also the motherboard of the device needed to be replaced. As a user, I cannot understand how a motherboard failure, which I cannot interfere with in any way, can be considered my fault. In addition, the constant failure of the water pump and the repetition of the same fault raise serious doubts about the product’s durability and quality. I request that this issue be handled as a recurring and chronic fault rather than user error, that the necessary repair be carried out free of charge, and, if this is not possible, that either a full refund be provided or the product be replaced with a new and fault-free device. Furthermore, I request a detailed technical error analysis report explaining the root cause of the repeated water pump failure and the alleged motherboard fault.