Consulting Room Pvt Ltd — fraud case online shopping

I'm very disappointed for this fraud and i want to complain about this fraud company, yesterday i was received a call and there was a girl who taking about my online shopping app id, she told me that i am flipkart customer executive and she told about my last shopping for flipkart so i was trust her and she told me that i[censored] shopping 5000 n above then we give u a axiting gift because u r our lucky customer so i was shop she also told me that the 60% cashback on this offer and it is instantly credited on ur account bt there was no cashback or any product when i was call back them they told me that u first u pay gst of this product after we send u the gift and the gst amount is 11999.07, and when i was requested them that i don't want any gift please back my money which i was pay u they told me that we can't help u u have to pay the gst amount other wise u lost ur money 5019 so please i want my money back plz plz help me.