No person, firm, or corporation engaged in the business of furnishing gas, natural gas, water, or electricity to consumers shall demand or require a consumer to deposit cash as security for the payment of any bills for such commodity to be furnished:
In case no such security can be furnished, a deposit not exceeding an amount sufficient to cover an estimate of the monthly average of the annual consumption by such consumer plus thirty per cent may be required, upon which deposit interest at the rate of not less than three per cent per annum shall be allowed and paid to the consumer, provided it remains on deposit for six consecutive months.
Any person, firm, or corporation convicted of a violation of this section shall forfeit all right to collect or receive any sum from such consumer for gas, natural gas, water, or electricity so furnished.
The making of any rule or requirement in conflict with this section, is forbidden, and hereby declared to be unlawful.
R.C. § 4933.17