In case of any failure to make and file a return required by this chapter within the time prescribed by law or prescribed by the commission in pursuance of law, there shall be added to the amount required to be shown as tax on the return a penalty as provided in Section 59-1-401. The amounts so added to any tax shall be collected at the same time and in the same manner and as a part of the tax, unless the tax has been paid before the discovery of the neglect, in which case the amount so added shall be collected in the same manner as the tax.