Keiser university Placed me in collections Fort Lauderdale Florida

Hi my name is shay and I reside in Florida and attended Keiser university. I was going to do there nursing program and due to work and things at home I passed all my classes and had a 4.0 GPA, but still needed to take the TEAS test. They withdrawed me from there school and now I have a balance of $2,400 that they put me in collections for, even though my federal aid should have covered it. Mind you I reached out to my loan officer in June almost July that stated he would look into and get back to me but he never did. This school does not setup you for success or should I say the people running it. All they care is about making money and themselves. I really hope I can take action here because my loan officer really screwed SME especially since I passed all there classes with A's. I'm wondering if I can sue them for this?