How will I get my money back

My brother was selling me half of his lot that i later found out there is no title or legal documentations regarding the lot. I first gave him P200,000.00 before i left Philippines when I went for holiday, then over a week after he asked for more, and couple of weeks after that he called me again to send him some money for whatever reasons so i decided to asked him to give some sort of document so i can put up some money to send but our conversation heated up when i pressure him to send me documents regarding the said piece of land, then i found out that his common law wife does not to sell it to me, so i said give me my money back and we don't need to carry on the transaction, i refused to send him anymore money.
Now he is angry and said i should give him some more money.
Please help me how i can get my money back.
Sad

send him a demand letter then file a case to rescind your contract and return the money.