California Code, Financial Code - FIN § 50504

(a) If an amount other than or in excess of the charges permitted by this division is willfully charged, contracted for, or received, in addition to any other penalties or remedies, the commissioner may order the licensee to refund to all borrowers charged the excess amount, the excess amount and the amount of the charge, both with interest at the rate of 10 percent per annum, calculated from the date the improper charge was imposed.

(b) If interest on the principal amount of a loan in excess of the amount authorized by this division is willfully charged, contracted for, or received, in addition to any other penalties or remedies, the commissioner may order the licensee to refund the excess interest amount to all borrowers charged the excess amount, with interest at the rate of 10 percent per annum, calculated from the date the improper charge was imposed.