Damage caused by forklifts>Private liability insurance

Hello, I have a problem with my insurance. It’s about the following: I have damaged a parked tank with the forklift, a friend. I have reported this to my private liability. Now the insurance writes to me after 2 months that there is no insurance cover, because the following is not covered: “Damn by the smoke of a motor vehicle. Since the forklift drives faster than 6 km/h and it is not a self-propelled working machine But I have looked through my insurance policy and there is also the following: “However, liability for damages caused by the use of first motor vehicles, – those only on non-public routes and parking without regard to a maximum speed and trailers; – with no more than 6km/h and self-propelled working machines with no more than 20 km/h -non-insurable trailers These vehicles are not subject to the exclusions according to paragraphs 1.2 2 and 2.4 3 of the liability insurance statements.” I have already written an e-mail to the insurance company with the reference to these sentences, but they still refuse. Do I have any chance, or do I not understand the text correctly and am really not insured in this case? In the appendix a scan from the corresponding page from the police would be made. I’m happy if someone here can tell me something, hopefully, positive.