Indian Army — scam in the name of indian army

Saw a deal on quikr for an iphone 7 plus that looked tempting. I pursued interest, and made an offer. I was contacted by the seller who was supposedly an army man. He wished to sell his mobile phone. The catch was that if i provided him my address, he'd ship the mobile to me, and accept cash in return. I agreed. He took an advanced payment of 1000. Kept repeatedly saying stuff like "army se hoon bharosa karo main beimaani nahin karoonga". I paid in advance and he said i will receive the phone the next day. The next morning, i was asked to make a transfer for 4000 for a "mohar". Basically, my package was an open package, so he required me to pay a fine for the same. After a series of incidents, he asked for another 4000. And another additional 4000 so for something known as gatekeeping. He kept forcing and urging me to pay. I then refused. Even when a senior colonel spoke to me and wanted me to trust him. I began to read online to find stories similar to mine. So i began to ask him to return the 8000 that i had paid previously. He said he'll do so on google pay,. But he smartly tried to take more money for me instead of returning it. That did not work out because i saw through him immediately. So currently, my 8000 rupees are with him. I need advice as to how i could report these people. I have screenshots and transaction receipts that stand as proof for the fraudulence.