Yes, there may be stiff penalties for employers who refuse reasonable accommodation requests. While courts can interpret human rights legislation, human rights tribunals in each province and federally are specifically set up to deal with complaints such as failure to accommodate an employee.
Both courts and tribunals might award an employee damages under human rights law, and may penalize employers with additional damages depending on their conduct. The most egregious cases of employers refusing to comply have seen human rights tribunals penalize employers for their conduct with damage awards into the six-figures, which have been subsequently confirmed by the courts.