Complaint Review: institute of medical education

I attended the school in 2009 for the Licensed Vocational Nurse Program. They received money I go t from FAFSA. I also paid out of pocket and had a Sallie Mae loan to cover the $24,069 tuition fee.Upon graduating and receiving my diploma.. I waited for the mail to arrive saying I can take my board test.It never came so I contacted IME. They said they would not send my paperwork in because they just reviewed my grades and said I got a "D" in Mental Health course so I'd have to repeat it before my BNVPT application would be sent in.I was confused because I had my dilpoma and graduated already. .. but I still came in and retook the coarse and passed. They teacher emailed them himself to say that i passed.IME then...emailed me saying they were not aware I was in his classes and that I would have to redo the course AGAIN. I cried and gave up and have felt so helpless. it is 2017 and i am still not a LVN but still am paying back my student loan? It's not fair and I must fight back now and see what I can do. I have let them push me around too much! please help me!