I wasn't allowed to travel internationally because of Transit Visa. Is it a legit reason for not using my tickets?

On November 28th, 2014, in Moscow, the airport Domodedovo, I had my valid ticket to the U.S. going through Moscow-Frankfurt => Frankfurt-Toronto => Toronto-Minneapolis, MN. I hold a F-1 U.S. visa, and am a citizen of Tajikistan. When I came to the check-in counter, handed my passport to the representatives to print me my boarding pass and check my luggage in, they told me I needed a transit visa transiting through Canada, not going through Germany, therefore they did not check me in nor gave me my boarding pass. I checked Canadian embassy whether I needed a transit visa it says YES. below is the snapshot:

Then I tried calling the Canadian consulate in Moscow but there wasn't anyone assisting visa questions. I tried calling the ticketing agency I purchased the ticket from but they weren't any helpful in rebooking different tickets using the same airline before my departure time. At the end I was forced to buy new tickets to fly to the U.S. My questions or was my ticketing agency supposed totl inform me via email to get a transit visa? Was it a legit reason for the representative at a check-in counter in Moscow not allowing me to use my ticket? Would I have a good reason to claim a report for some kind of refund saying the agency didn't inform me I needed a transit visa? Or is it always up to the travelers to know they need it?

Thanks! I'm just a full-time student and spending extra $650 is just too much for just not knowing about this Canadian transit visa.