What is the ruling on the money the questioner received from a governmental institution in the form of salaries after being dismissed from work, and how can he rid himself of it, and is it sufficient to hand it over to an official in the administration, and what is the ruling on the items he purchased with it?

What was deposited in your account by mistake must be returned to your workplace. Your action of using it is impermissible, knowing that you are not entitled to it. There is no harm in benefiting from furniture and similar items that you purchased with that money, as the money is tied to your liability. Charity with the money is not sufficient as long as you are able to return it to your workplace.