well, since no one seemed to have received this promo, might as well memorialize here in case they run it again:

Today, I finally got this resolved, 27 days later.
- Finally got the first email from Avis, but instead of a live html based email, it was a screenshot so the 'book now' link was just a photo, not a live link. Said a coupon should be attached to my Avis profile, but a) it wasn't and b) no Coupon code was provided.
- After 15 emails with both Avis (useless) and Air Canada (thankful I am SE) with no one ever hearing about the promotion, the Concierge team told me they had escalated to "the appropriate department" and I should expect a response.
- I finally got a phone call from someone in 'execute support' at Avis yesterday. She was awesome, and very apologetic.
- She went ahead (yesterday) and booked my reservation for me, but still had to FedEx me 5 paper coupons to bring to FL with me in March to Avis to get my rental for free... yes, FedEx'd paper coupons.

So, in the end, it's a great 5 day free SUV rental over school break, so it's worth the $450 I saved, but man, was it a hassle to get.

Hopefully either no one else gets this promo, or they figure out a better way