What affirmative defenses can I use for a University vs ex-student lawsuit??

I attended University a few years back. I could only attend for a few semesters before I had to drop out because I had no money. They then sued me and I am preparing the answer now. The complaint is very short , it really only lists the amount and my name. Are there any standard affirmative defenses I can use? - Is this your question? Add additional information