Every stock insurance company organized under the provisions of sections 379.010 to 379.203 shall quarterly pay a tax upon the direct premiums received during the calendar year, whether in cash or notes, in this state and on account of business done in this state at a rate of two percent per annum in lieu of all other taxes except taxes on real and tangible personal property, taxes on incomes and on franchises and license taxes; provided, that such insurance companies shall be credited with cancelled or returned premiums, actually paid during the year in this state.