Return of Borrowed money from Friend

I had given 3300000 Rs to my friend for home renovation last march (27th march 2018).In bank transfer i had given 1800000 and remaining money hand over it in cash transaction.We had made agreement of it and notarized but in April-2019 with no witness sign on it as it was made only for reference and no cheque No. mentioned on it. He had given me 2 cheques (15Lk & 18Lk) but i came to know that he had requested to bank for stop payment of both cheques. He had given me 800000 in bank during April-May-2019. Now my friend saying that i gave him only 1800000 and refuse to return the remaining money and said he has to give me only 1000000 Rs. Now in this case how can i get back my money and what possibilities of the same. As he saying that i had not gave him any cash money and i have no receipt of the same. please guide me to solve this issue as he warn me that if i go to police then he will report the case that i threaten him to sign the document and now i am asking to pay the amount of agreement.