For each plan there is essentially an A and B for it, A being the currently listed speed, and B being the old D2 speeds.
With a D2 modem it will only allow their system to add the B plan. With a D3 it can actualy have either plan associated. So likely when you got the d3 it was switched, but the plan was not. This happened to me as well (idiot at the store).
Give them a call up and they should be able to switch you over. (Not sure but this plan MAY require the Hitron d3, so you might have to exchange).
I know I got the speed increases. The Internet is much faster for me now. Interesting to know about "ANOTHER" new modem. When I renewed my contract in October then JUST got a new modem and swapped it out there.... If I have to get another new modem it will suck because it usually takes like 3 days for them to get it online rofl. This will be like 5th new modem I have gotten from Rogers........
The only reason I have even became aware of the new limits is because oddly we have been going over our limit, when we usually only use about 50% of it. Calling them now (on hold for about 10 minutes sigh). I have bad luck with Rogers support, so I really hope this goes smooth.