Must money taken fraudulently from young people on chat, by deluding them with the prospect of meeting a girl, be returned, knowing that repentance has already occurred, and does it fall under the ruling of money taken through disobedience, which does not have to be returned?

If a Muslim repents from an unlawful act from which he acquired wealth, and if he has already spent that wealth, then there is nothing upon him. However, if the wealth is still in his possession, he must dispose of it by spending it on charitable causes, and he is not permitted to return it to its owner.