Not sure what consumer rights you have in Slovakia, but I would try perhaps seeking some assistance here if you have any organisations of this type. I had significant problems with Triumph with my speed twin. Like you I engaged with the delership and when I did not get anywhere I requested that they write to Triumph, which they did. When they did not get any joy I got an addrerss from them to write to the factory. Sent the letter with tracking so that the factory have to sign for it at delivery. Until you can get Triumph to acknowledge your problem it will be difficult to get any resolution.