This happened on my car after an oil change (not at Canadian Tire) and they did the same thing. Zap straps to reattach the bottom (plastic in my case) because the old bolts had rusted through. They never mentioned to me either, but fortunately I still had 4/6 original bolts still in place.
I get that an oil change customer doesn’t want to hear “uhhhh we found some broke shit that’s going to cost extra to fix”, but it’s not an acceptable alternative to half ass a shitty fix and not tell anyone. It’s like opening up the walls in your home for the first time and discovering the insanely lazy job a plumber or electrician hid behind a wall.