Ontario Highway Traffic Act

i want to know if anyone can help me out, i got pull over back in may last yr and the cops show me the radar telling me i was doing 79km in 50km zone which is 29 over 3 points ticket but at the end she give me a ticket that is 80km in 50km zone 4 points ticket....and the fine was $140....and i was just ckecking ticketcombat.com over 30km should be ...