Okay, so I contacted Canada Customs for my package that has been sitting in Mississauga since March 1 (and I paid a crapload of money for expedited shipping!!!!). Turns out that Canada Post receives their packages, and hold them IN CASE customs decides they want to review them. In other words, Canada Post keeps your package in a warehouse to be processed by THEIR customs broker... NOT the CBSA. (Unless the CP broker flags it as restricted materials or something).
In other words, it's not Canada Customs holding the package, it's effin' Canada Post. (And I called, but of course, they're not open yet).
Someone is going to reimburse me for the extra shipping. (grumble grumble)