Bosch Dryer Came Back Broken From Maintenance, It Shuts Itself Unexpectedly

We had our separate dryer, which is more than 10 years old, cleaned and serviced because a licensed service technician who came to fix another appliance told us to. It was sent back to us on November 16, 2023. The first time I used the machine, it worked fine. But after 15 minutes, it would either shut down and reset itself or show an error on the screen. We called the service again on November 24, 2023. They found a problem with the mainboard that was making the machine shut down when it got too hot. It was strange that they said this problem had nothing to do with the general cleaning and maintenance that had been done earlier and that it could have happened or would happen anyway. Even so, they offered to lower the price of replacing the mainboard from 7,000 TL to 6,000 TL so that the customer would be happy. It just so happens that there is only one mainboard available across the whole country for my machine, which adds to the confusion. In the end, we had to call the authorized service again to avoid more trouble. Our machine was already in good shape before the general cleaning and maintenance, but we paid 2,400 TL for the service, which included 1,700 TL for the cleaning and another 700 TL for a new belt. However, the machine couldn't be used two days after the maintenance because the motherboard stopped working. As soon as I told Bosch customer service that I wasn't happy with their service, they denied any wrongdoing and said it was going to happen anyway. I don't want to hear about divine decrees that were already made. All I want is for my machine, which used to work perfectly, to work again, even if it takes two hours to dry instead of 1.5 hours. I hope that the strange thing that happened to my mainboard, which used to work, also happens to the last mainboard that is still in Turkish warehouses, making it useless.