How do I write a complaint letter to TWC against a school?

Ok so I went to a vocational nursing school for 13mnths and finished the entire program, never failed one class. They decide to give a final exam (not required by the state of Texas) at the very end to determine if you "graduate" or not. If you don't pass it, not only are you unable to take the State Exam (Nclex-pn) but you also are terminated by the school. I worked so hard the entire year meeting all passing requirements, doing all my clinicals and deserve to take the state board exam. I hear that the school is currently under investigation and was told to write a letter to the TWC filing a complaint. How do I start..what do I say/do?