or any regulation, practice or service complained of, shall be found to be unreasonable or unjustly discriminatory, or the service shall be found to be inadequate, the commission shall have power to fix and order substituted therefor, such rate or rates, fares, charges or classification, as it shall have determined to be just and reasonable and which shall be charged, imposed, and followed in the future, and shall also have power to make such orders, respecting such regulation, practice or service as it shall have determined to be reasonable and which shall be observed and followed in the future.
"a. The commission may, when complaint is made of more than one rate or charge, order separate hearings thereon, and may consider and determine the several matters complained of separately, and at such times as it may prescribe. No complaint shall at any time be dismissed because of the absence of damage to the complainant."
The following is the simple language in which the great power to fix rates is couched:—
