How can I legally recover my money?

My girlfriend ordered many things online, and I always paid for them. I also gave her many gifts. Now we have broken up. When I asked her to refund the money I spent on her, she said she won't return anything. She also said that if I ask for the money again, she will file a case against me. If I tell her parents anything, she threatens to file an FIR against me. I returned all the money she spent on me, but she refuses to return mine. What should I do?