At&T might charge you from every bill.....
just look at your statement every time they sent, and make sure how much you should pay. sometimes they will charge you from 9.99-19.99 as third part company required. Kin Scott, customer supervisor from AT&T explained that they will refund to you after 20 days if you don't like that service, but that's not good behavior you suppose to do as a such big company! if you just paid without any wondering, they wil charge you every month since then , because they assume you join the plan!!!
so, just pay more attention to look at you bill from AT&T, they are not dependable company!