All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
As long as this work involved cheating, then the wage received in return for it is unlawful. It is incumbent on you to repent to Allah, The Exalted, and dispose of the money you were paid in return for this work by spending it on public interests and good causes such as spending on the poor and needy, building mosques, hospitals, and the like. Ibn Taymiyyah said: “If the commodity or service is unlawful – such as the fees paid to a prostitute or the price of Khamr (alcoholic beverages) – and the seller has not yet received the price, he is not given legal right to receive it. If he has already received it, then Islamically, he is not to give it back (to the payers), because it would constitute helping them in the sin. In other words, they would be getting both the unlawful benefit and the price they had paid for it. Moreover, this money is unlawful for the prostitute and the seller of Khamr and the like (to benefit from). Instead, it should be spent on the interests of the Muslims. If this prostitute or the seller of Khamr happened to repent and were poor, it is permissible to give them from that money in proportion to their need.” [Majmoo‘ Al-Fataawa]
Allah Knows best.