so, I was contracted to write a text messaging client for windows. I said I wanted $250 upfront and $250 upon completion. He only sent $200 so I completed it but made it crippled and put "demo" in the titlebar and he told me "this is just some demo you downloaded. I am not giving you any more money" so I changed "demo" to "cheapskate version - that means you dave" and sent it again now he won't answer my emails