Thank you. Yes, as I said a little above your post, I already had filed with DOT. Declined. It was the airline who answered my claim, not the DOT.
To me that is strange... I first thought that it was the airline reaching out for a solution and then DOT will ask me if we agreed on anything. No, it does not work this way. I guess I complain to DOT and DOT sends it to the airline to handle the case any way they wish... Hmmm.

Not applicable in this case, I am not a U.S. citizen.

Thanks... No. Delta will not help with anything, as they said the fight was operated by WestJet (although bought on delta.com under 006 ticket number).
Also, cannot charge back: I was not incorrectly charged - the ticket I purchased WAS used for flying OK. WestJet did get me there, although one day later.

The major expense is a hotel room which could not be used. I understand that under the conditions of the insurance, this does not even qualify as an expense, as it was not bought during the time I was stuck. Also, my travel insurance is against DELAY, but not a CANCELLATION. And technically, my flight was cancelled. Which caused my arrival to the destination with a delay -- but by canceling the flight instead of delaying, the airline washed its hands and they do not need to pay anything :-))
A compensation for the delay from the airline would at least offset this, but then the airline lies about the reason for delay/cancellation. THAT is the most crucial problem.

I seem to be exactly the kind of a victim in a case with no solution.
That is OK, I lost more in life than $1000.

Thanks! I will remember that!