It does sound right. Nextel requires once you have a BB that you have a Data Plan. I would suggest if you still want to use the BB as a PDA,

then change the Data Plan to one of the cheaper plans, then if you are using the BB Web Client, log in, go to the Filters option and there will be an option to stop forwarding emails to the BB. You'll just have to fight the temptation to surf the net. Just a thought!