Whenever the commission shall find, after hearing, that the rules, regulations, practices, equipment, appliances, facilities, or service of any public utility, or the methods of manufacture, distribution, transmission, storage, or supply employed by it are unjust, unreasonable, unsafe, improper, inadequate, or insufficient, the commission shall determine the just, reasonable, safe, proper, adequate, or sufficient rules, regulations, practices, equipment, appliances, facilities, service, or methods to be observed, furnished, constructed, enforced, or employed, and, after hearing, shall fix the same by its order, rule, or regulation. The commission shall prescribe, after hearing, rules and regulations for the performance of any service, or the furnishing of any commodity, of a character furnished or supplied by any public utility. On demand and tender of rates, such public utility shall furnish such commodity and render such service within the time and upon the conditions provided in such rules.