Pay back my hard-earned money!

500,000 RMB of my money was cheated by them, plus money from my family brought the money cheated by them to around 700,000 to 800,000RMB. The platform has closed down since 20th July. They made up all kinds of tricks trying to persuade us not to call the police. Now we don't know who we should turn to and how we going to survive this.