Calling card used to be proof not anymore. I never had any chance to use unlimited call to Bangladesh. I used per per use 3 cent per minutes. Before BD Gov used to charge 2 cent per minutes for incoming isd call to bd now they increase to 3 cent per minutes. Now i pay 4.3 cents per minute.
If you have unlimited calling plan to Bangladesh , there is no unlimited always there is a limit, if you passed 3000 minutes per month then your account red flag. Since BD Gov increase charge so minute will be reduce. In Montreal no one give unlimited or any VoIp company
. Only Bell Canada give unlimited call to 60 countries include BD mobile and landline. Line is not always clear.
Since 2 years maybe more CRTC ruled number has to be show (Dialer number) even you call by using calling card.
When you call BD ask them if your number shows other end then BD BTCI receive 3 cents from your telephone provider and line will be clear if shows any BD number not your real phone no then BD BTCI receive nothing and line will not clear, buggy, noisy.
I use per per use bit costly but clear voice. In my home i always have Bell Canada unlimited 60 counties. They charge 34.99 per month.