If the department, after a hearing upon complaint or on its own initiative, determines that a charge by any contract carrier by motor vehicle or any carrier regulation or practice affecting a charge contravenes the policy in RSA 266-A:1 or gives an unreasonable advantage to any carrier in competition with another carrier, the department may, after giving consideration to the cost of the carrier's service and the public interest, order:
RSA 266-A:19
1941, 224:19. RL 304:19. RSA 376:19. 1981, 435:34. 1985, 402:6, I(e)(7).