I agree with Lyle's creative idea...if your cousin really is as self-centered and disorganised as he sounds (I think McGrath had the right of it most likely) then a letter, or most likely even a small claims lawsuit wouldn't help one bit...but by personal phone calls, making yourself a pest now that he has money (as he did to YOU hmm?)in his pocket and reminding him of the debt, I think you could be the squeaky wheel that gets the grease and eventually get your money back.

One other VERY important thing...have you told him all that you've told us? About how betrayed you felt, and how you felt you had defended him and got nothing in return? If you are counting on him to be able to figure these things out himself, I wouldn't. You really can't assume he can read your mind, and perhaps if he really understood how you feel, he might have more incentive to get your money back to you. He used a guilt trip on you once, so turn about is fair play I'd say...clear and concise emotional communication sometimes works wonders!