how to claim a publisher?

hello, i'm a indie game developer, back in 2015 i made a game (2d space shooter) with plans to publish it on the android market place for free, to start collecting some experience in the game development business.

i found a publisher that told to me to sell the game on steam, he convenced me to sell it on steam and after some days i agree to publish the game.

that fact is, the publisher sold the game at $0.99, after two year and a half he only sent me $600, when i asked, he always told me…

how to claim a publisher?