All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
It is impermissible on a Muslim to use cheating and lie for unlawful earning, since Allah, The Exalted said (What means):” O ye who believe! Be careful of your duty to Allah, and be with the truthful.” [At-Tawbah/119].
Thus, a Muslim is prohibited to circumvent the terms and conditions set by people in charge for unlawful earning as he will be punished in the hereafter, for the Prophet (PBUH) said (What means):” There is no flesh raised that sprouts from the unlawful except that the Fire is more appropriate for it.” [Related by At-Tabarani].
In addition, being treated unjustly doesn’t entail a person to use circumvention for unlawful earning; rather he should observe piety because Allah, The Almighty said (What means):” Whoso believeth in Allah and the Last Day is exhorted to act thus. And whosoever keepeth his duty to Allah, Allah will appoint a way out for him,” besides, He said (What means):” And whoso keepeth his duty to Allah, He will remit from him his evil deeds and magnify reward for him.” [At-Talaq 2-5].
Therefore, whosoever took subsidy unlawfully is obliged to take it back to the Ministry of Finance Income and Sales Tax Dept. since they have special account and fund for retrieving subsidies that were taken unlawfully and without any legal prosecution. And Allah knows best.