What is the ruling of Islamic law regarding an employee who collects money from consumers and writes "account ledger" on the receipt for an amount less than what was paid, under the pretext of taxes, knowing that he has a percentage of the money paid and has already spent it?

The forgery, deception, and betrayal committed by an employee are not permissible, based on the Almighty's saying: "And avoid false statement," and the Prophet's (PBUH) saying: "Whoever cheats us is not of us," and "Deceit and treachery are in the Hellfire." Whoever is entrusted with collecting water fees must adhere to what has been agreed upon between the water company and the consumer, without increase or decrease. Whoever increased them must return the excess; if he consumed it, he must return it from his own money, otherwise it remains a debt upon him.