Getting back my deposit

I paid $300 deposit to reserve an apartment. The manager told me the prices were locked so I put in my application and paid the deposit. About 2 months later, he told me the price went up (almost $100 more). So I told him that i would not want to live there if they change the price like that. And I asked for my deposit back. He said he would talk to his boss to see if he can keep the price for me, and said that I could get my deposit back if thing did not work out. Thing did not work out indeed! But he told me I could not get my $300 deposit back! he kept going against his word. Would this be a valid complaint? Is it likely that I would get my money back?