It's a pretty crappy thermal design for sure. This is the trouble with young kids doing design work these days, they don't understand many simple fundamentals such as thermal management. The fins on the heatsink resting on the floor should be exposed to open air for example. The aluminium bars linking them to the supplementary heatsinks at the top are clearly a 'kludge' to try and improve a poor initial design.
The plain alumium heatsinks on the other PCB are likely just part of the switching PSU and may be perfectly adequate.
Can you AFFORD a law suit ? I would use whatever consumer protection laws exist in the Netherlands to make the manufacturer withdraw or modify the design.
Graham