How to recover your money legally?

I deal in Solar Panel & Installations. One of my employee belongs to SC/ST Community, who had taken 35000 advance from me, in last 2 months. Now, he is not coming on work and also not returning that advance taken by him. Thereafter, he has now uploaded a Facebook post against me and saying that I had called him with caste remarks but I have never said any such remarks to him or any one else. His allegations are totally false and baseless. He just want to grab some more money as extortion from me. In this regard, please guide me so that I can save myself from his false implications.