Billing email keeps changing

I have had problems with my billing being sent to the wrong email account since before December 2016.  I have contacted Hughes at least 3 or 4 times, with 3 different case numbers,and have also changed the email back to the correct one at least 7 or 8 times.  The lastest was on 09/17/17 Case #106269833 via chat.  I've been checking every couple of days and it was fine until today (9/29/17) and it changed back to the incorrect email.  In the lastest chat I was told I didn't change it under the billing information (which I did) so she changed it again.  Can anyone on this forum give me some kind of idea how to get this fixed since calling and chatting don't seem to work.