687.09 Persons accepting chattel mortgage as security for loans under $100 to cause amount as principal, interest, and fees to be inserted.—Every mortgagee accepting a mortgage on personal property as security for the repayment of a loan of money less than $100 shall cause to be stated in such mortgage, separately and distinctly, the several amounts secured as principal, interest and fees, and any mortgagee willfully violating the provisions of this section shall forfeit all interest and fees secured by such mortgage, and be entitled to recover only the principal sum.