If I had more time on my hands I would've bought a pass for the auto show and set up shop at Mazda's booth showing people looking at the car what could happen. Maybe that would've got their attention.
Oh yeah...that would certainly work. You'd then be escorted out of the event, of course. A little story regarding your idea...
After being nice, polite and patient, for nine months...one sunny spring Sunday afternoon I'd cleared out the model home's shoppers raising Cane due to lack of proper corrective action regarding many documented issues we had with our house. After it became apparent to the good and caring folks there I'd accomplished my mission, I was told never to set foot in their model again or "they'd have me arrested for trespassing." "No problem, public parking lot, right out front, works just as well". Same tactics were employed years later regarding a whiny Jeep Wrangler xfer case and an Explorer rear main seal oil leak. Nice, polite, patient, inconveniencing me, yadda, yadda...zero satisfaction. As with the townhouse episode, only thing that got results unfortunately, was making a precise and composed 'scene' allowing potential customers to here it all. I have no problems, or reservations, with planning and executing these tactics after the, shall we say, "civilized" methods fail to produce favorable results. Far more cost effective than getting involved in the sleazy legal system, which, for the dollar amounts discussed here, not worth the squeeze.
Any rate, thanks for posting all of your findings and maybe in time you'll be able to recoup your losses. FYI, loyalty and relationships, for the most part w/ auto dealers at the very least, is long dead. In fact, I think being loyal creates more financial 'harm' to consumers than any benefits gained when you're in need. Sad to say, but that's been my experience.
While I'm not in Canada, it might be nice for others in your locale to know the name of the body shop that actually was sympathetic to a situation you had not created nor could even avoid. Apologies if you did mention them and I missed it.
Cheers