Mich. Comp. Laws § 487.807

Sec. 7. The state treasurer shall, when his attention is called to violations of any of the provisions of this act, refer the same to the attorney general, who shall proceed, when warranted by the evidence, to collect the penalties as herein set forth; and all suits or proceedings for the violation of any of the provisions of this act shall be first commenced in the circuit court of the county in which the business office of said person or firm is located.