If, in any action authorized by Section 1241, judgment is rendered for the plaintiff, the amount of the judgment shall first be credited on any contributions, interest, and penalties due from the plaintiff under this division, and the balance of the judgment shall be refunded to the plaintiff. In any such judgment, interest shall be allowed and paid only to the extent that interest and penalties collected under this division are available therefor, at the rate of 12 percent per annum upon the amount of contributions found to have been illegally collected from the date of the payment of the contributions to the date of the judgment.