I send 7000 euro to a guy from Serbia to get me...

You must file a complaint with the Public Prosecution office or the nearest police station or through the website of the Ministry of Interior on the Internet: The Ministry of Interior
Or by notifying the Department of Combating Computer Crimes and Information Networks at the Ministry of Interior in New Cairo, or by calling the hotline (108), which was reported for electronic crimes. As for the legal basis, you were subjected to the crime of fraud according to Egyptian law
Article 336
Detention shall be the penalty inflicted on whoever attains the seizure of cash, bids, debt securities, clearance bonds, or any movable goods, and that was by fraud to take away all or some of the wealth of others, either by using fraudulent methods that would accuse people of the existence of a false project or a fraudulent incident or creating hope for a fictitious profit or paying the amount that was taken fraudulently or deluding them into the existence of an incorrect debt bond or a forged clearance bond, either by disposing of immovable or immovable money that does not belong to him and does not have the right to dispose of it, or by taking a false name or an incorrect description. As for whoever initiates the swindle and does not complete it, he shall be punished with imprisonment for a period not exceeding one year, and the offender in the case of recurrence may be placed under police notice for a period of at least one year and two years at most.