You can take two steps. First, you can report the matter to the police at their headquarters located near the Crazy signal. They will call him and tell him to sort out the issue. But these people are crooks and they would hardly pay heed to calls from the police but you can still give it a try. Ultimately, when this crook does not act over the calls from the police, the police will ask you to seek assistance from the court of law.
If you lodge a complaint at court located in Dafna, You will need to be present at each date of hearing and if you don't your case will drop. He can on the other hand avoid attending the hearing several times giving one reasons or another. This whole thing cam go on for several months. The crook knows all this very well. At the final hearing, the court may force him to pay. Your friend will get his money back, but after several months of running to and fro to the court.
How many people can afford the time for this. The crook knows all this well, and hence his game with your friend and others.