<human>: Here's the quick version of the story: Had a boyfriend I lived with, found out he was a huge liar with issues, and ending up breaking up. It was pretty much like going through a divorce without lawyers when we split. He moved out immediately (his choice), leaving me with our two bedroom apartment that, as a poor grad student, I'm having trouble paying for while looking for a new roommate. He owed me $1500 (a lot of money to me) when we broke up. I kept some of the furniture and knocked what he owed me to $1000.

He told me he would pay in installments. I've been very nice about not pressuring him and trying to be cordial. I only bring it up about once a week. He's told me multiple times a check is in the mail and a check never comes. I end up talking to him, he ignores me or says that he's busy, then finally we talk and he will tell me that he just A. never got around to it or B. has other financial obligations and will send me money on a given day. The money never comes and I'm starting to get pissed. He moved into a new apartment with someone, so he is still splitting bills, while I'm on my own. 

People tell me that the money is lost forever probably, but I really need it. It's not like $50 or something. I've thought of showing up at his work, but I really don't want to harass him. He's really starting to grind my gears, however. I trusted him and he continues to lie even after the break-up!

How can I convey to him that I'm serious? That I'm not just going to let this go? Any ideas? My friends joke about Judge Judy, but since I don't have anything in writing that's signed, I feel that I'm pretty much screwed. ANY ideas appreciated on how to deal with this!

Condense the text into a few key points
<bot>: Have ex-boyfriend who is not paying me back $1000 he owes me. Need ideas on how to get him to pay up!