I think in a way, at times, we are lucky they don't do their job better, as Mark has said, you can't really bash them for doing their jobs. I think we have all gotten caught trying to job the system, it's more on us for trying to do something that's not always legal instead of on customs agents that are actually good at their jobs.
Just curious when you get shipped to Canada from the US is there an option to just refuse the shipment, even though that would seem like a dick move saying "oh I don't want to pay the duty on these so I don't want them", but is that an option or do you just get the bill and have to pay it, never had to deal with this so I'm kind of curious how it works in another country. Better luck in the future!