Looks like you and I are reading different subject titles ... the subject title I read for this thread says "Beware bad customer service Canon Direct" ... not sure what you consider "not blaming Canon", but that title, to me, clearly says that the OP is blaming Canon, especially when it is the very first post by the OP and disappears for 4 days.
People should take the time to learn about the dos and don'ts of how to use their credit card before blaming Canon. I do not think the OP is blaming Canon,
It is bad customer service. Sorry, but there is no way to sugar coat that.
From the first message of the OP:
They are always out of stock. Two days ago they became available and I ordered immediately. Today I called as I had received no shipping notice and was told me order was cancelled due to a "hard reject" of credit card. The CS woman would give no info, no reason and when asked why I was not notified she said "we don't do that ........
........ Although my order was form a US card, with a verified US billing address and shipped to that same address, it was still cancelled."
Now forget the logistics, but if you had purchased something from Canon, B&H or Amazon, or one of the other big companies, and it was cancelled, but the company did not even bother to send you an email, wouldn't you be a little annoyed?!
That is bad customer service, and that is what the subject line is about.
Even if it was a boiler plate email telling the guy/gal to (insert word of your own choice) off, that would be better than simply ignoring it all together, especially if it is true that it is on a US cc, using a US address which is the same as the US billing address.
Good customer service would have been to contact the person by email, hold the item for 24 or 48 hours and tell them that there are issues with the order and could he/she please contact them asap or the order will be cancelled.