Problems with the car tax L200

Hello! Maybe someone can help me here. The change in the car tax especially in the area of the pick-ups is probably the hardship. When I bought my L200, I got to leave it as a truck. The tax office says it is not bound to the classification of the registration authority and sent me a decision correspond to the car tax. The reason was that for double cabins the area for the transport of persons is larger than that for goods. So I let the booth load up. Now the story starts from the beginning. Does someone have an idea how to get out of this mess again. Would I be pleased. Greetings to all L200 drivers out there.