(a) This subchapter may be enforced only through a qui tam action brought under Subchapter C.
(b) No other direct or indirect enforcement of this subchapter may be taken or threatened by this state, a political subdivision of this state, a district or county attorney, or any officer or employee of this state or a political subdivision of this state against any person, by any means whatsoever, except as provided in Subchapter C.
(c) This section does not preclude or limit the enforcement of any other law or regulation against conduct that is independently prohibited by the other law or regulation and that would remain prohibited by the other law or regulation in the absence of this subchapter.