Alright...seeings how noone wants to give you any advice.
Continue to borrow as much money as you can from the girlfriend, grandmother, whoever. Always promise to pay her back though. That puts some kind of contract to the borrowing, and will make her feel better if she ever has to take you to court. DO NOT write any kind of IOU. If you do, try to put it in girls handwriting so if you get to court you can claim that is not your handwriting, and that it looks like one of her friends wrote that on a bar napkin. Wouldn't hurt to stain a little lip gloss or makeup on the paper/napkin as well.
Once the small claims judge sees the handwriting and make-up, her credibility will be instantly shot. Oh, and don't let anyone except for her grandmother hear you ever say you will pay her back.
The other thing it does is makes her hang onto your ass a little longer. If you play it right, you may even leverage some blowjobs out of it.
Saying things like, "Either blow me or I'm done" Or, "Just shut up and suck it, if you want me to go to work tomorrow."
These are sure fire blow job lines. If she says "no", you gotta walk out and not answer your phone for a couple hours. GUARANTEED to work, especially if you owe her a few thousand bucks.