Not Just Cancel his power but also make a formal complaint against him.
1st make the cancellation. Use form 5476
Section C – Cancel the Appointment of a Representative
Question 9
Fill in this section if you wish to cancel the appointment of a representative. Write the representative's full name. Thanks for yr suggestion mate , yes definately i wil do what u hav said , i hav already decided to do so but would u mind telling me how to send the cancellation form plz? My file was in process with date in oct 2010 too . Thanks.
then make a complain
http://www.cic.gc.ca/english/information/representative/complaints.asp
teach him a lesson that this was the last scam of his life. I'd sue him in the court.