(1)    All instruments, contracts or securities providing a rate of interest exceeding the rate allowed in s. 138.05, 138.051 or 138.052 shall be valid and effectual to secure the repayment of the principal amount loaned in excess of $2,000; but no interest may be recovered thereon except upon bottomry and respondentia bonds and contracts.

   (2)   Any lender or agent of a lender who violates s. 138.05, 138.051 or 138.052 may be fined not less than $25 nor more than $500, or imprisoned not more than 6 months, or both.

   (3)   Any borrower who paid interest on a loan or forbearance at a rate greater than the rate allowed in s. 138.05, 138.051 or 138.052 may personally or by personal representative recover in an action against the lender or personal representative the amount of interest, principal and charges paid on such loan or forbearance but not more than $2,000 of principal, if the action is brought within the time provided by s. 893.62.

   (4)   Any borrower to whom a lender or agent of a lender fails to provide the statement required in s. 138.05 (4) with respect to a loan or forbearance may by himself or herself or his or her personal representative recover in an action against the lender or the lender’s personal representative an amount equal to all interest and charges paid upon such loan or forbearance but not less than $50 plus reasonable attorney fees incurred in such action.

   (5)   Notwithstanding subs. (1) to (4), if any violation of s. 138.05, 138.051 or 138.052 is the result of an unintentional mistake which the lender or agent of the lender corrects upon demand, such unintentional violation shall not affect the enforceability of any provision of the loan contract as so corrected nor shall such violation subject the lender or the agent of the lender to any penalty or forfeiture specified in this section.

   (6)   In connection with a sale of goods or services on credit or any forbearance arising therefrom prior to October 9, 1970, there shall be no allowance of penalties under this section for violation of s. 138.05, except as to those transactions on which an action has been reduced to a final judgment as of May 12, 1972.

   (7)   Notwithstanding sub. (6), a seller shall, with respect to a transaction described in sub. (6), refund or credit the amount of interest, to the extent it exceeds the rate permitted by s. 138.05 (1) (a), which was charged in violation of s. 138.05 and paid by a buyer since October 8, 1968, upon individual written demand therefor made on or before March 1, 1973, and signed by such buyer. A seller who fails within a reasonable time after such demand to make such refund or credit of excess interest shall be liable in an individual action in an amount equal to 3 times the amount thereof, together with reasonable attorney fees.

   (8)   This section does not apply to a loan or forbearance made on or after November 1, 1981.