The worst exchange office in Prague lost a lawsuit against the CNB. It gave tourists only 15 crowns for the euro
Chequepoint operated exchange offices on Wenceslas Square, Old Town Square and Republic Square in Prague. In a dispute over the licence with the Czech National Bank, a company operating a network of exchange offices fell. The company was violating the law that determines the basic rules for the operation of exchange offices. For example, the company did not disclose to its clients the amount of money it was buying euros from them in crowns. The Central Bank therefore revoked its licence. Its decision was upheld in a subsequent court case. Aktuálně.cz has the judgment at its disposal.
Source https://aktualne.cz/chequepoint-praha-cnb-soud/