2013 Model Opel Corsa 1.3 Engine Diesel  Radio Code Unknown

I have a 2013 model Opel Corsa 1.3 engine diesel vehicle. I am the 3rd owner of this vehicle. The vehicle is at 151 thousand km. The service light of the vehicle is on and the fault cannot be found. I went to Ankara Opel Opal authorised service. 4. They said it was a spark plug malfunction. The spark plug had already been replaced with Bosch brand spark plug. They deleted the fault with the computer. 3 days later it came on again. They could not find another fault. Anyway, I wanted to remove and install the battery terminals, but since there was no radio code, I first requested the radio code from the dealer. They could not provide it either and said call Opel customer service and they would give it to you. While I was at the authorised service, I called Opel customer service and had them contact the authorised service advisor. They could not agree between them either. They said we opened a record and we will return after 2 days. We said OK. They returned on the 3rd day. They said Ms K**** will help you at Opal authorised service. We said OK. We went to Opal to Mrs Kübra between work and work. She looked at the system and said it was not visible. She said it was paid to break the password. She said it would cost around 2000 TL. He called an officer by phone but had a little tension with the officer. Then Mrs Kübra directed us to the industry by saying that they break this password cheaper in the industry and could not help. In short, if you have trouble with OPEL on this issue, they direct you to the industry. We were stuck in this issue. At least give us the radio code, we said, the huge OPEL could not help. I don't know how you can find a solution, but I don't want to deal with OPAL authorised service.