"SECTION 249. Interest. -

"(A) In General. - There shall be assessed and collected on any unpaid amount of tax, interest at the rate of twenty percent (20%) per annum, or such higher rate as may be prescribed by rules and regulations, from the date prescribed for payment until the amount is fully paid.

"(B) Deficiency Interest. - Any deficiency in the tax due, as the term is defined in this Code, shall be subject to the interest prescribed in Subsection (A) hereof, which interest shall be assessed and collected from the date prescribed for its payment until the full payment thereof.

"(C) Delinquency Interest. - In case of failure to pay:

"(1) The amount of the tax due on any return required to be filed, or

"(2) The amount of the tax due for which no return is required, or

"(3) A deficiency tax, or any surcharge or interest thereon on the due date appearing in the notice and demand of the Commissioner, there shall be assessed and collected on the unpaid amount, interest at the rate prescribed in Subsection (A) hereof until the amount is fully paid, which interest shall form part of the tax.

"(D) Interest on Extended Payment. - If any person required to pay the tax is qualified and elects to pay the tax on installment under the provisions of this Code, but fails to pay the tax or any installment hereof, or any part of such amount or installment on or before the date prescribed for its payment, or where the Commissioner has authorized an extension of time within which to pay a tax or a deficiency tax or any part thereof, there shall be assessed and collected interest at the rate hereinabove prescribed on the tax or deficiency tax or any part thereof unpaid from the date of notice and demand until it is paid.