Roborock Service Charged Extra Fees Twice Despite Warranty

I purchased my Roborock 9 robot vacuum cleaner about 3–4 months ago, and it is still under warranty. I sent it to the service center because a small part broke while it was climbing onto a carpet. The rest of the device was perfectly fine—only that part was damaged. However, the service center claimed it was a user error and charged me ₺5,800, which I paid by credit card. They told me the product would be delivered within three to seven days. Today, I was called again and informed that a motor malfunction had been detected, and I was asked to pay an additional ₺2,200–₺2,300. When I first sent the product to the service center, I was told a clear price would be given after inspection, and I would be informed of the total cost. Calling again to demand extra payment after I already paid the first amount is both unreasonable and completely against customer satisfaction. Moreover, when I called customer service, they offered no help, and when I said I would file a complaint, they replied, “Of course, you can,” and hung up on me. I bought this product for ₺21,000, and having so many expenses and repeated additional charges within three months is unacceptable. I request a refund of the overcharged amount, free repair of the product, and a detailed follow-up from customer service. I expect my grievance and dissatisfaction to be resolved urgently.