OK, but I refuse to spend $100/mo on my cell phone plan and to save money, especially after accumulating a ton of "rollover minutes that never go away but somehow always do", I switch to a lower number plan. Since they always remove some of the rollover minutes when I need them, I always end up with a bill that shows me going over the total allowed. How they time this so accurately, I don't know.

I tell them that I think it's wrong that they do this and that I know the customer survey showed ATT coming in dead last and that I have no problem taking my cell phone and internet business somewhere else, so they always remove some of the charges and make sure to ask if i have been completely satisfied, blah, blah, blah. They'll end up doing the same thing with internet use. They'll never go to a true "pay for actual use" plan because they can grab more money if they have plateaus.
As they say, "It's easier to ask for forgiveness than to ask for permission".