Negative experience with LB-acoustics

I have had a negative experience with LB-acoustics Messgeräte GmbH. Through their sales manager, Mr. Zbyněk Hruška, we were supplied with measuring equipment with an impedance tube for measuring sound absorption. Unfortunately, it contained many defects. Some of the tube diameters were not manufactured according to standards (they were inaccurate). In addition, an incompatible microphone calibrator and low-quality microphones were delivered. As a result, the equipment does not measure accurately. Furthermore, they refuse to repair everything at their own expense!
Mr. Hruška is an unreliable, arrogant, and above all incompetent person who has absolutely no understanding of the issue at hand and should therefore not be doing this job. He should be replaced by a qualified person who understands the issue.
Given the delivery of poor-quality measuring equipment of dubious origin and Mr. Hruška's unprofessional behavior, I strongly advise against working with LB-acoustics, let alone purchasing any measuring equipment from them!