Within two years after the date on which payment of contribution, or interest thereon, is made, an employer, who has paid such payment or interest, may make application for:
(1) An adjustment thereof in connection with subsequent payments.
(2) A refund thereof if adjustment cannot be made.
If the commissioner determines that payments and interest were erroneously collected, he shall make the adjustment, without interest, in connection with subsequent payments of the employer, or if such adjustment cannot be made, refund the amount of the payments erroneously collected, without interest, from the clearing account of the unemployment compensation fund, and the amount of the interest erroneously collected, from the employment security special administration fund.
For like cause and within the same period the commissioner, on his own initiative, may make an adjustment or refund: Provided, That nothing in this chapter shall be construed as permitting a cash refund of any contribution required under the law in effect when such contribution became due.