Sec. 21. (a) Except as provided in subsection (b), a provider shall not:
(1) prohibit or prevent completion of an intrastate collect calling call made in connection with an inmate calling service; or
(2) decline to establish or otherwise degrade intrastate collect calling made in connection with inmate calling services;
solely for the reason that the provider lacks a billing relationship with the called party's communications service provider.
(b) The prohibitions set forth in subsection (a) do not apply if a provider offers debit calling, prepaid calling, or prepaid collect calling for intrastate inmate calling services calls.