Maybe I will put it this way for you.
Had you not been viewed as an alleged malinger, if you really went to Private Hospital or Polyclinic to get MC, the most they can do to you is to ask you back to endorse your MC.
However, given that you have been viewed as an alleged malinger, don't give them the reason to find problem with you. They can say that you were told that if you are really that sick that you cannot go back camp to see MO, then you can go A&E, if not you cannot go Polyclinic and Private Hospital. If you still go, go Polyclinic and Private Hospital, maybe they can charge you for disobeying orders, but then they still have to honour your MC if the MO endorsed it.
The question is why are you keep playing MC? Sounds so suspect.