(a)(1) The commissioner may, for good cause, extend the time for making any returns required under this article for not more than 30 days.

(2) No extension granted pursuant to paragraph (1) of this subsection shall be valid unless granted in writing upon written application and only for a period, as appropriate, of not more than 12 consecutive months or four consecutive calendar quarters.

(3) Upon the grant of any extension authorized by this subsection, the dealer shall remit to the commissioner on or before the date the tax would otherwise become due without the grant of the extension an amount which equals not less than 100 percent of the dealer's payment for the corresponding period of the preceding tax year.

(4) No interest shall be charged by reason of the granting of an extension pursuant to this subsection during the first ten days of each extension period. Thereafter, interest shall be collected upon the unpaid balance of the dealer's liability at the rate specified in Code Section 48-2-40.

(5) This subsection shall apply to all extensions granted pursuant to this subsection on or after July 1, 1980, and to all extensions granted pursuant to this subsection and in effect on July 1, 1980.

(b) In the event any dealer fails to make a return and pay the tax as provided by this article or makes a grossly incorrect return or a return that is false or fraudulent, the commissioner shall make an estimate for the taxable period of retail sales of the dealer and the gross proceeds from rentals or leases of tangible personal property by the dealer and shall estimate the cost price of all articles of tangible personal property imported by the dealer for use, consumption, distribution, or storage for use or consumption in this state. Based upon his estimate, the commissioner shall assess and collect the tax, interest, and penalty, as accrued, on the basis of the assessments. The commissioner's assessments shall be considered prima facie correct and the burden to show the contrary shall rest upon the dealer.