Trouble With Cellphones

The more I learn about cellphone companies the more I dislike them. My sister racked up a cellphone bill of over $200 one month last year. This occured because she did not know how to check how many minutes she had left. I recently obtained a cellphone and due to a loophole I used up all of my minutes the first day I got it. All that the phone manual said about aim is that when you get on aim on your phone it costs money only for outgoing messages. Knowing this I decided to stay on aim 24/7 on the phone so i could recieve messages and see who was on anytime. Later that night I got on my account on my computer and messaged people alot. Apparently my cellphone company couldn't tell the difference between my computer and my cellphone while I was on the same account and they charged me 0.10$ per aim message I sent. From all of my past knowlege about these companies I'm very surprised that people put up with these poor business ethics. I pay 20$ a month for only 80 minutes ): (Its a pay as you go type) My parents are going to allow me to get a normal type if I can find a good deal. If any of you know of a good deal with a good company please feel free to post it. Thanks