Interested in Case Management--lost as to where to start

Hi all! I am an RN in FLA with 24 years of clinical experience. I have decided, after much debate, to pursue case management. I'm lost as to where to start . I understand that you have to have 1 year of experience in the field to sit for the exam,but don't understand where to get the experience. I spoke with the Director of Case Management in my facility, and even interviewed for a position that required no experience. I was not given the position, and asked for feedback, but no response. I feel my current manager might have had something to do with this. I currently work on a "nightmare" PCU unit. Our patient/staff ratios are ridiculous,we work frequently with 5 complete care patients, and are always short a tech, so we are expected to "do it all". The "uppers" seem to take extreme pleasure in finding the one thing that wasn't completed than looking at the fact that nothing catastrophic happened in a 12 1/2 hour shift with no break. We are reprimanded for clocking in 1 minute early, while nothing is said about consistently having to stay late to complete charting. There are just 5 hospitals in the immediate area, unfortunately, 3 are owned by the corporation I work for. There is a large metropolitan area approx. 1-1/2 hour away with many more larger hospitals. What can I do to make myself more marketable for a beginning CM position? I would greatly appreciate any and all advice ! Thanks in advance !