Direct TV scamming the elderly?!

Has anyone else had a problem with Direct TV's billing that they have tried to resolve and were unable to do so?  My parents are 88 and switched from Cox to Direct TV.  Their bill was supposed to be 159.47 + taxes per month.  They were told that their first bill would be higher because it would have one-time charges--it was $406!  I called and went over the charges line-by-line so that I could explain them to my Dad.  At this time, I was guaranteed that their bill would be $159.47 + taxes going forward.  NOT THE CASE! Their second bill was $224 and their third bill was $313!  I called Direct TV and they refuse to make any adjustments and said my parents only recourse is to cancel and pay a $400 early termination fee.... then they can try again to get the package they initially wanted.  The Manager was rude.  I asked to speak to her superior and she told me no, she was the Manager. I'm both shocked and angry!  I would like to know if anyone else has had this problem, particularly if it involved older customers.