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, sallallahu ‘alayhi wa sallam, is His slave and Messenger.
An employee is trusted to do his job in the best manner possible. Allah the Almighty says {What means]:" O ye that believe! betray not the trust of God and the Apostle, nor misappropriate knowingly things entrusted to you."{Al-Anfal, 27}. He the Almighty also said {What means}:" O ye who believe! Fear God and be with those who are true (in word and deed)."{At-Tawbah, 119}. In addition, the Messenger of Allah said:" And he who treats us dishonestly does not belong to us.”{Related by Muslim}.
According to Sharia, one who embezzles or steals is obliged to make repentance to Allah, and amongst the conditions of this is returning the embezzled funds to whom they belong. The Messenger of Allah said:" “The hand that takes is responsible for what it has taken until it returns it.”{Related by Abu Dawoud and Tirmithi}. It is permissible for the person whose money had been embezzled to reach an understanding with the embezzler and he is also allowed to go to court so that the latter receives the suitable penalty.
In all situations, the embezzled isn`t allowed to take any increase over the amount that is his. This is because the Messenger of Allah said: "There is no injury nor return of injury."{Related by Ahmad}. Moreover the discretionary punishment is within the jurisdiction of the Muslim ruler or whoever represents him according to the law. Moreover, individuals or institutions aren`t allowed to implement such punishment on their own.
In conclusion, the syndicate isn`t allowed to impose any increase over the sum embezzled from it since this is considered eating up people`s wealth unjustly. And Allah the Almighty knows best.