General duties of public utility.

Each public utility shall furnish to each person applying therefor reasonably sufficient, adequate, and efficient service upon terms as required by the commission. No public utility shall be required to furnish electricity or gas for resale except that a public utility may be required to furnish gas for containerized resale. All rates and charges made, demanded, or received by any public utility for any service rendered, or to be rendered by it, and each rule and regulation of such public utility, shall be fair and reasonable. No public utility shall make or give any undue or unreasonable preference or advantage to any person or locality, or subject the same to any undue or unreasonable prejudice or disadvantage in any respect.