Did you check out any of the stores I suggested??? I suggested like four, but as I said without a general location I'm pretty much at a loss to look any further.
https://www.rona.ca/en/farm-supplies
https://thefeedstore.ca/
https://sharpefarmsupplies.com/animal-nutrition/animal-nutrition-backyard-poultry/
There were just a few I found with a quick google search that sell for backyard keepers. I couldn't google anything specific for your region since...
https://www.tscstores.com/ is this where you were looking?
I'm not super familiar with Canada to be honest, but I know plenty of Canadians keep chickens so there's surely got to be something.
Is Chewy an option? Their feed is good, but a little more than you'd pay in a feed store.
Any feed supply store. Walmart even sells poultry feed. I'm not trying to make you feel bad, but it's honestly a wonder the birds even started laying and didn't have stunted growth! It's THAT critical to feed them a feed formulated for poultry! Imagine a human trying to survive on corn and...