Ala. Code § 37-1-83

Upon a complaint in writing made against any utility by any mercantile, agricultural or manufacturing society, or by any body politic or municipal organization, or by any affected person, that any rate, service regulation, classification, practice or service in effect or proposed to be made effective is in any respect unfair, unreasonable, unjust or inadequate, or unjustly discriminatory, or unduly preferential, or constitutes unfair competition, or that the service is inadequate or cannot be obtained, the commission shall proceed, and without such complaint, the commission, whenever it deems that the public interest so requires, may proceed, after notice as provided in this division, to make such investigation as it may deem necessary or appropriate; but no order affecting such rates, service regulation, classification, practice, or service complained of shall be entered by the commission without notice and a hearing. Any utility may make complaint as to any matter within the provisions of this title with like effect as though made by any mercantile, agricultural or manufacturing society, body politic or municipal organization, or other person. However, when any such complaint in writing is filed, the same shall be set down for hearing within 90 days from the date of the filing thereof, which said hearing may be continued for an additional period not to exceed 90 days, unless the parties to said proceeding agree upon further continuance.