BELL AND SOLO, SHIFTY HIDDEN FEES, NO TRUST EVER

Hey guys, from the general mood in here, should I not suscribe to preauthorized credit payments on my new solo phone? My first bill, after a week of service is already twice what I agreed to, partly due to a mysterious data charge that was never made clear to me via the website or the salesperson, I was thinking about agreeing to a ten dollar unlimited incoming on top of my 25 dollar plan, will this help me fight these obvious crooks for the next two years or will giving them more excuse to overcharge me?