(1) Where an assessee, within one month from the service of a notice of demand, makes an application and satisfies the assessing authority that he was prevented by sufficient cause from appearing as required under section 14, or that he did not receive the notice issued under that section or that he had not a reasonable opportunity of being heard, the assessing authority shall cancel the assessment and proceed to make a fresh assessment in accordance with the provisions of section 14:
Provided that no application under this sub-section shall be entertained by the assessing authority if tax admitted in the return is not paid.
(2) Nothing contained in sub-section (1) shall apply to an assessment which has been made the subject-matter of an appeal under section 28.
(3) No appeal shall lie under section 28 against an order passed under this section.
(4) Every order passed under this section shall, subject to the provisions of sections 29, - 11 - 31, 33 and 34, be final.