Come on guys, the debt collector gets the loan for a cut rate, the bank has already written it off and on sold it.
There is great advice on this thread but leaving uni to get a job to pay off a debt is not good advice. As many have said, try and come to an arrangement. They would prefer part of the money now rather than long term so maybe you can strike a deal and pay off your Dad over time.
Don't worry about "the taxpayer". Your tiny amount will hardly effect the amount of tax payed by the debt collector.
It's not leaving uni, it's postponing uni. Nothing wrong if he can get a job in his field before finishing uni, you can always come back to it.
Better yet, work part time and study full time, as others suggested.