Online dating fraud

First I contacted them for relationship enquiry then they said need to make an registration fee of 1050 to continue further and I did then they asked my photo and Aadhar card and I have sent them too. Later I received few girls photo and later I came to know this is not the site I was looking for then next day they called and I said to cancel my registration they said I need to make a payment of 5090 to as cancellation fee and I paid and then they asked for 10000 for cancelling the photo and Aadhar as documentation cancelling fee, then they demanded 23000 to verify my account details but now I came to know it was a fraud then I informed I can’t make the payment and after few days they started to blackmail stating we will send legal notice and police will come to your home as such. Then after few months they called and informed I have talked with my team and they have agreed to reduce the amount 11500 so if I make the payment then everything will be completed. But I refused to pay now they are saying we will send legal notice and sue you. What steps should I take now??