Rogers cell phone billing = confusopoly

I got my bill yesterday and if you look and the underlined printing I subscribe to their 6 Gigbytes service for $30. I also pay $17.50 / month for 200 minutes of day time cell use. What concerns me is that extra data usage bill of $25.04.  It doesn't make sense to charge 100 times more per MB just because I didn't pre know how much data I was going to use.
Can Rogers make money from irritating their customers?  Do people still buy when they are confused about the billing?  I am tempted to phone and cancel the service. What do you think? Is Rogers practising confusopoly? Should I cancel the service? Thanks for listening to my rant!