Mich. Comp. Laws § 474.135
The department may alter, suspend, or revoke an authority issued under this act if the department determines in a contested case hearing held under chapter 4 of the administrative procedures act of 1969, 1969 PA 306, MCL 24.271 to 24.287, that a motor carrier to which an authority has been issued has willfully violated or refused to comply with this act. If a motor carrier is found operating a bus for the transportation of persons after its authority has been revoked under this section, the department may compel compliance with this act by proceedings in mandamus, injunction, or other appropriate civil remedy. The proceedings described in this section may be brought in any county in which the alleged violator may be sued or in Ingham County circuit court.
MCL 474.135