I am not sure whether this will help you guys or not but it helped me a lot.

I was using my palm treo and I used some edge for downloading some stuff and get billed for $30 odd dollars. I phoned Rogers customer service and they take that off from my bill. I further advised them to disable my Edge from my account which they did. So even I accidentally browse web, I will get an error.

Now, I am using wifi on my iPhone at home at my work at public places for the last 2 months and I am not getting charged for DATA.

So, Please call Rogers and tell them to disable Edge from there end, if you don't want to use Rogers Data Plan at all. You can phone them later on to get it enabled whenever you need it back.

Hope that will help.