Assessment of non-filers of returns- (1) Notwithstanding anything to the contrary contained in section 73 or section 74

(2) Where the registered person furnishes a valid return within thirty days of the service of the assessment order under sub-section (1), the said assessment order shall be deemed to have been withdrawn but the liability for payment of interest under sub-section (1) of section 50 or for payment of late fee under section 47 shall continue.