Canada Post Can Be Aggravating

Just as this post title says, sometimes Canada Post can be aggravating.

• I'd ordered an item online from Amazon.ca and was following its progress via its Canada Post tracking number.   My order left the warehouse in Ontario and arrived at a Canada Post sorting facility, a mere 40-60 minute drive from my address, on the same day -- where it promptly stayed for two weeks.  Did it fall behind a counter or something?
• After the Canada Post lock-out ended earlier this year, all I received was junk mail for the first week or so before receiving any legitimate mail.
• Another example:  I knew Canada Post had attempted delivery of an order because I had its tracking number.  However, when I returned home there was no delivery notice in sight.  No biggie, since I was still able to pick up the package at a local post office using the tracking number.  The aggravating part?  A week after picking up the package, I finally received the failed delivery notice in my mail box. 
• At my current residence I receive an inordinate amount of wrong mail -- correct address, incorrect recipients (I assume previous residents).  Each time I dutifully write "not at address" on the envelope and send it back to Canada Post.  Aggravation?  When weeks later I receive the exact same letter, AGAIN.  Do I really need to write "not at address" twice? Should I capitalize?  Highlighted in nice red ink?