In case any return filed pursuant to this article shall be insufficient or unsatisfactory to the Village Treasurer, he may require at any time a further or supplemental return which shall contain any data that may be specified by him, and if a corrected or sufficient return is not filed within 20 days after the same is required by notice from him, or if no return is made for any period, the Village Treasurer shall determine the amount due from such information as he is able to obtain and, if necessary, may estimate the tax on the basis of external indices or otherwise. He shall give notice of such determination to the utility liable for such tax. Such determination shall finally and irrevocably fix such tax, unless the utility against which it is assessed shall, within one year after the giving of notice of such determination, apply to him for a hearing, or unless the Village Treasurer, of his own motion, shall reduce the same. After such hearing he shall give notice of his decision to the utility liable for such tax.