You may need to sue your employer: you can file a legal action, representing yourself if need be, seeking a court order (injunction) requiring them to turn over whateve documentation you need and also forcing them to assist with whateve other reasonable requirements you have for Medicaid. Usually you will first send them written notice that you will take legal action if necessary (often, a good idea is to send copies of the notice to HR, to the president's office, and to your former manager), which will hopefully motivate them to act.