Penal Act of Offenses Against National Currency Article 4

A person who, for the purpose to gain, does not exchange coins or notes according to the legal exchange rates shall be fined 10 times of the amount of the profit thus obtained.A person who engages in the money exchange business and charges a fee or commission over 1% of the nominal value of the coins or notes to be exchanged shall be subject to the same penalties.
中文原文 妨害國幣懲治條例第4條
意圖營利,不按法定比率兌換各種幣券者,處所得利益十倍以下罰金。
以兌換幣券為業,所取兌換手續費,超過幣額百分之一者,亦同。

English translation for reference only; the Chinese text prevails. Not legal advice.