Can recertified FMLA be dennied if a required class is taken during the time specified ?

I had an ruptured diviticuli which resulted in abdominal abcess and two hospilizations with surgery. I obtained the required paperwork from MD and submitted and was on FMLA leave from july 10th to the second week of september. I still had time left on the 12 week limit, but ran out of funds on my short term disability. I returned to work, with MD instructions not to lift anyone weighing more that 150lbs (with another person helping me). I work as an RN in a hospital. I returned to work , and experienced tearing pain upon lifting, and found I had diminished strength to lift. I notified my MD and my job and obtained an extension of FMLA while calling in sick. My job reveiwed the FMLA and dennied it due to my having attended a required recertification class for ACLS (advanced life support)during the specified FMLA extension. I was not told that this would affect it. The class if not taken would have prevented me in returning to work upon completion of the extended FMLA. I was put on suspension (working) and have continued displinary action relating back to this event. I have now been told that I can not miss one hour more of work without being fired. This unrealistic expectation continues till 2011. (9mths). The initial problems started in July 2009, with extension denial in Sep of 2009. They use a rolling point system,that looks at six months at a time, and then frezzes with an incident. (going to a 12 mth system starting in July 2010) I am now being denied the ability for position changes, funds for school and any advancement in this facility. Of note, I have had a snow emergency in Jan 2010 (1 day), migraine with call off in Feb 2010 (1 day), and a week of GI problems in April, of which my MD is not certain is related to the orginanl problem or not. My hospital does state in it's manual that an employee, who is out sick and then attempts to return to work, only to find that they are not yet well enough to return to work would not be penilized for the attempt. I have found that they do not even consider this statment. I would not have returned when I did, if not for this statement.