Section 18. If not later than three years after the date of payment of any amount as contributions, payments in lieu of contributions, interest, penalty, or fine, an employer who has made such payment shall make application for an adjustment thereof in connection with subsequent contribution, interest, penalty, or fine payments, or for a credit thereof in connection with payments in lieu of contributions, interest, penalty, or fine payments or for a refund thereof because such adjustment or credit cannot be made, and if the commissioner shall determine that payment of such contributions, payments in lieu of contributions, interest, penalty or fine was erroneous, the commissioner shall allow such employer to make an adjustment of the amount erroneously paid, without interest, in connection with subsequent contribution, interest, penalty, or fine payment by such employer, or shall credit the employer's account with the amount erroneously paid, or if such adjustment or credit cannot be made, the commissioner shall refund from the Unemployment Compensation Fund or from the clearing account in the Unemployment Compensation Fund or from the contingent fund, as provided in sections eighteen and fifty-eight A, without interest, the amounts erroneously paid; provided that the commissioner shall not allow any adjustment in connection with subsequent contributions, for amounts of interest, penalty, or fine collected subsequent to July first, nineteen hundred and sixty-six, nor shall he refund any such payment from the Unemployment Compensation Fund. For like cause, within the same period, and subject to the same conditions, adjustment, credit, or refund from the Unemployment Compensation Fund, the clearing account in said fund or from the contingent fund, as appropriate, may be so made on the commissioner's own initiative. Refunds of contributions, interest, penalties or fines pursuant to subsection (e) of section six shall be refunded by the commissioner in accordance with the provisions of said section, without application.

Within nine months after the receipt by the applicant of written notice from the commissioner that he has denied an application for a readjustment, credit or a refund of any contribution, of payment in lieu of contribution, in whole or in part, which application has been filed by an applicant who has paid a contribution or payment in lieu of contribution under this chapter, such applicant, in addition to any other remedy which the applicant may have, may bring a civil action against the commissioner to recover the whole or any part of such contribution or payment in lieu of contribution. Such action may be brought in the district court department in the judicial district of which, or in the superior court department for the county in which, the employer lives or has its principal place of business, or in the municipal court of the city of Boston. In case the court shall find that the whole or any part of such contribution or payment in lieu of contribution was excessive or has been collected or imposed incorrectly or unlawfully the court shall enter judgment accordingly in favor of the applicant and against the commissioner but to be repaid out of the clearing account, and such judgment without interest shall be so paid. No applicant shall be entitled to the remedy provided in this paragraph upon any issue which has been raised in a proceeding brought under any provision of subsection (d) of section fifteen.

If, within three years after any contribution or payment in lieu of contribution has been paid, the commissioner shall determine that an employer has paid insufficient contributions, payments in lieu of contributions, interest thereon or penalty assessed in lieu thereof, the commissioner shall require such employer to make an adjustment thereof, with interest, in connection with a subsequent or additional payment, or shall so charge the employer's account as appropriate.