Bangladeshi Passport, Travelling from Vancouver to Dhaka

Yes, your itinerary is definitely eligible for 24 hour visa free transit and you don't need any kind of visa. By the way Syed, you have wrongly mentioned the time of your departure from Shanghai Pudong... It should be 9:15pm (21:15).

You will print out your flight tickets and have those printouts with you. Also, you will declare at check-in in Vancouver that you will travel to Dhaka, Bangladesh, via China using 24 hour visa free transit. After a short inspection, you will be allowed to board the plane.

Upon your arrival in Beijing, you will approach 24 hour visa free transit counter where you will apply for a temporary entry permit by declaring the same thing and also present your tickets. You will be granted a permit free of charge because your next flight will be a domestic one. As I can see, your entire journey will be on China Eastern, so you will ask at check-in in Vancouver whether your luggage will be tagged all the way to Dhaka. I assume that this will be the case, but you should ask, just for a case.

The Vancouver consulate is saying, I will need visa.
The china visa application center in ottawa is saying if I transit more than one city, they suggest me to apply for transit visa.
The consular section of the chinese embassy in ottawa is saying I do not need a visa.

This is very confusing

Embassies and consulates were never the best place for question regarding this subject. They are relevant for visas and status issues, but transit options are entirely under the jurisdiction of the Chinese immigration. Totally different ministries. You don't need a visa!

I see. But I heard many cases, where passengers went to the airport and they were denied boarding pass at the check in counter. What do you do in that case?

Syed, honestly, I can just tell you if your itinerary is within the legal frames of Chinese visa free transit rules. From your presentation I can clearly see that your itinerary is eligible and within all the necessary legal frames. Also, I don't see any possible obstacle for you to be allowed normal boarding in Canada and also your acceptance in China to perform your confirmed flight itinerary.

It is also hard to comment what has really happened to the people that went to the airport and been denied boarding. Maybe they had ineligible itineraries, maybe their layover in Urumqi was longer than 2 hours, maybe their itinerary was exceeding 24 hours... Maybe they have encountered an inexperienced member of the staff at the counter and they did not ask for his/her superior to look into Timatic to check whether you are really eligible or not. Who knows? Since you are eligible, if something of this kind happens to you, you should always ask for a superior and require that your itinerary is checked thoroughly in Timatic knowing that this official source for this time of subjects will tell everything in your favor.

Beside this, I really don't know what to tell you more than that. I wish, I could be that member of the staff, but unfortunately I'm not. You will be fine, you will see and after your journey, you will come here and confirm that we were right about your journey :)