What to do when there is a property dispute between the family

Dear Sir/Madam, we have a flat in my father and brother's name, not in my name. I had contributed in the loan of the same. Now, i wish to depart and I have asked for my share. They are denying that I won't get money, right now. They are telling me that whenever the flat will be sold, they will pay me the share. I am in a hurry to leave the house because of some family issues. I wish to buy my own new home and thus i need money. What should I do? I have proofs of Money Transferred from my account to the account from which the loan installments had deducted. I had made NEFTs to their joint savings account of SBI, from which the money got transferred to loan accounts. I am asking them to make three parts and give me my share. They are not denying but also they are not giving the money or taking any stand. Yestreday, i had tell them that i would have to take any legal step, if they dont take any stand. Please advise.