How to put stay on under construction property

Hello everyone, I seen a under property in navi Mumbai ulwe and as per discussion with the developer he have the 1 unsold flat in the property so I discuss with him about the costing and he ready to give in 33 lacks and I paid him the 5lakh73thousand token amount including registration amount on developers request but after paying this he only given us the property draft which he made for us and said I will take the registration date only after getting loan sanctions from the bank so I took sanctions from the nationalise bank and given him but after that also he is not ready to register the flat and he put new conditions towards us that he wants to talk with banker and bank manager about loan disbursements also he wants disbursements within a 2 days then after also I given call to him with banker and bank manager. and they told him to do the register first then after getting property registration documents within 5 days we will give disbursements So after that also he is not satisfied and he put new conditions that he wants a written statement letter behalf of bank from me ( written by developer and want signed from me it means it will look it's given by me) that bank will give disbursements within 5 days if he. Doesn't get the disbursements then after am giving him the authority to sell the property to another customer without intimate me So I regret his condition and I told him I will not sign on any of this paper because disbursements is not in my hand also on phone call bank manager told him that they will give within a 5 days but still he want me to sign that letter. After next 2days later developer sent a letter to my house that he is not Willing to give the property to me because I kept his outstanding amount and therefore he will cut 10 % from my given amount and return the remaining amount So I called him and Asked about the letter which he sent to me so he told he having right to cut the 10% amount so I told him I was not kept your any outstanding amount then how you will cut also I have bank sanction letter but you are not ready to register the property then how will bank disburse the money ( while talking with him I comes to know he need black money) And after this argument he told he is not willing to sell the flat and he will give my money within 1 month also but after completing 1 month he didn't given me my single rupees and from his office person I comes to know that he already sold that flat to another customer but he showing me that he didn't sold Now almost 2 months complete but he didn't paid me my money So can any one help me on this please give ur valuable suggestions so I can fight with him