Misleading information when i got new service

I just opened a new account with 2 lines come to find out it is costing me money than what I was originally told. my first line is 85.00 my second is 45.00 plus 20.00 a piece for line usage plus my monthly payment of 23.97 on each phone.  I had no idea there was going to be the extra 40.00 for line usage. So my bill was going to be 180.00 something plus taxes and surcharges (also wasn't allowed to use my 8% discount on the choice plus plan) not interested in watching HBO etc on my device all I wanted was to be able to call, text, Facebook and browse the web. to make it a little cheaper I switched to 3gb well that was all used up in one day, so they offered me 6gb and now it is almost gone. so I am stuck with paying for 2 new iphones my bill running almost 200.00 I have no data left this is totally useless to me.  What really is crazy I was on a prepaid plan for 45.00 a month and never ever ran out of data. I have chatted 3 different times with agents and all information should be on my account, but each time I have to repeat myself.  The agents should be held responsible for the information that is misleading to the consumer, I am paying all this money to AT&T and I have no use for the phone or service, it is doing me no-good. So I am stuck with a service I really won't be able to afford now.