43. The Minister may re-determine the duties, interest and penalties and make a reassessment or an additional assessment, as the case may be, (a) at any time, if the operator or the person who filed the return
i. has made a misrepresentation that is attributable to neglect or wilful default or has committed any fraud in filing the return or in supplying any information provided for in this Act; or
ii. has filed with the Minister a waiver in prescribed form within 4 years from the day of mailing of the notice of an original assessment or of the notification that no duty is payable for a fiscal year;
(b) within 7 years from the day of mailing of the notice of an original assessment or of the notification that no duty is payable for a fiscal year provided the operator
i. has amended the return for the fiscal year in accordance with section 43.2, or
ii. would have amended the return for that fiscal year pursuant to section 43.2 had the time limit prescribed in that section not expired;
(c) within 4 years of the day referred to in paragraph b in all other cases.