Friendly loan to relative not returning back

I gave 1 lac loan to my brother in law, 3 yrs and 1 month back in 2019.He borrowed it in the name of buying property but bought a four wheeler without informing me.He took the cheque in the name of his wife who is my elder sister.He promised to repay back in 6 months.They didn't returned the money till 2021.After multiple requests they started paying me in small amount every month till July 2022.Now,they have stopped paying me and use abusive language and threatened me. They have returned only 40,000 .How can I get my rest 60,000 from them ?I had sent legal notice but no response from them.I filed online complaint in CM portal uttar pradesh and the issue was escalated to police station. The police contacted my sister through phone ,she said that she has returned the rest 60,000 by cash and hung the call.She is not picking their call.My brother in law said to police that the cheque was issued in her wife name ,so contact her not him.Police closed the complaint.I can't afford court fes.