Ouch. Why can't people pay attention when they drive?
I was rear-ended at 50kph too, stopped at a light on Lawrence, east of Keele.
Focus was written off. (Less than 10,000km and only 8 months old.)
Took it to European Autobody.
Your insurance cannot force you to take it anywhere.
Also, tow drivers are NOT ALLOWED to even suggest shops.
The rental car must also be EQUIVALENT in class. (I got a Kia Sorento for a few days before being replaced by a 320i.)
Hope it all gets sorted out soon.