direct tv direct tv took $ out of our bank acct without our permission on several different occasions Internet

our direct tv was overdue..my husband checked our bank acct on christmas eve to find we had -$11 left as direct tv had gone in on several different days and taken as much money as there was to take out.  we had never authorized auto draft and only used one time payment on internet.  he called direct tv and was told we agreed to this when we signed our user agreement.  they said they had every right to go in and take what was owed to them.  the problem is, what if there is a dispute as to how much money you actually owe them?  you dont have time to discuss any discrepencies or errors prior to funds being taken from your acct.  to add insult to injury, they did this on christmas eve of all days...when people are strapped.  we literally didnt have gas money.  i cant fathom this is not illegal and am looking into our alternatives.

the scariest part to me is the fact that they re-visited the acct many times to get multiple withdrawls.  im scared to death they will take my entire social securiy check when it comes to pay for the cable box deposit or remotes or something like that.  how devestating that would be!  is there any recourse and has anyone experienced this and actually got their bank to reverse the charges?