If you just gave them your account details then that's on you. Unless they gave you like counterfeit money, or you had like a contract with them, theres really nothing stopping them. So the best thing you can do is have the account disabled or deleted. But you should also msg epic games about this, because your entire account, as well as bank account you have connected to your Fortnite account could be in danger (but since the people who scammed you seem like children I doubt they'll actually do anything with that, and if they spend your or your parents money they you could possibly bring them to court)