Without reading 5 pages...
I just refreshed my plan, having been a rogers customer for about 9 years now.
I was paying about $78 total for my Iphone 3g a month and managed to get more out of my plan and now paying about $63 total.
The key to working out a good deal is to have some ammo. Look at Fido, Telus, etc and look at comparable plans. See what they offer for similar pricing. See what kind of incentive they can give you for being a continued customer. Ask them to be honest about what they can give and not give.
By the end of my call, I felt like I could have gone for coffee with the girl, a bit of a "chatty Cathy."
I picked up my iphone4, was charged an activation fee and $10 for a new sim card. They told me I'd be reimbursed by rogers, so I called in and the guy said it was not standard policy to charge for a replacement sim card on a new activation, but would not budge to give me back the $35 activation. I thought it was BS, since I've had it waived in the past, was starting another 3 year plan, etc. In the end I gave up on it and they gave me a credit on the sim card on good will.
coles notes: have a reason to get a deal. ie. comparison shopping, long term customer, see what you do/don't use on your current plan and see how that can be converted to an area of use that you'd prefer. I think if you've done your homework, they appreciate that, rather than just calling up and yelling and saying "give me a deal."