That could be effective.
However, I find it hard to imagine how it could be administered. In effect, monetary penalties are generally associated with violations other than substantive violations. How will the Office of the Commissioner of Official Languages determine that there has in fact been a substantive violation and that a service has not been rendered in an official language? They will still need to prepare a report, conduct an investigation, and so on. That could then lead to a more substantial penalty than a simple amount of money like we would impose under our system.