(a) The commission shall establish the limit on the amount a provider may charge for a pay telephone coin sent-paid call in the local exchange company’s toll-free calling area.
(b) The commission may establish a statewide ceiling on the amount a provider may charge for a local pay telephone call that is:
(1) collect;
(2) operator assisted; or
(3) paid by credit card or calling card.

(c) The commission may not establish the ceiling under Subsection (b) at an amount that is less than the applicable local rates for such a call imposed by any of the four largest interexchange telecommunications carriers operating in this state.