One plus 7 - Mobile phone not delivered

I have ordered oneplus at flipkart app * on march ****, now it is **** june , they stated march ** it will be delivered date and since now not delivered after paying *****rs online, after calling flipkart repeatedly daily they use to give a hope it will get delivered now then or yes we will update your concern without providing any valuable informations, they made me to frustration and by giving false hope more than *times that it will be delivered definitely on now like that, that will be delivered . And i paid my money and they kept my money with them for * months without any information that it will be cancelled , they automatically cancelled now having my money saying that it cant be delivered really they cheated me and freely using my money for * months.