((a)) ** .—** If the Federal Government makes an overpayment to a contractor under a contract with an executive agency subject to this chapter and the overpayment was due to the submission by the contractor of defective cost or pricing data, the contractor shall be liable to the Federal Government—
((1)) for interest on the amount of the overpayment, to be computed—
((A)) for the period beginning on the date the overpayment was made to the contractor and ending on the date the contractor repays the amount of the overpayment to the Federal Government; and
((B)) at the current rate prescribed by the Secretary of the Treasury under section 6621 of the Internal Revenue Code of 1986 (); and
((2)) if the submission of the defective data was a knowing submission, for an additional amount equal to the amount of the overpayment.
((b)) ** .—** Any liability under this section of a contractor that submits cost or pricing data but refuses to submit the certification required by with respect to the cost or pricing data is not affected by the refusal to submit the certification.