Time for some hardball.
Your fence is standing strong. Let's put it under power. Where mandatory—such as when seeking damages—mzb.de is prepared to work hand in hand with a lawyer of your preference or suggest a competent colleague to team up with for the case at hand.
It is you who was ordered to cease and desist or accused of infringement? Be sure to anticipate the impending attack. If desired, mzb.de may perform long-term monitoring of your competitors' portfolios to mitigate your exposure.