Device Management - CAN'T LOG OUT OG HACKER DEVICES!!!

Since DirecTV bought ATT TV Now, I can no longer manage the devices my account is logged into. I have been trying for HOURS to get technical support for this and no one could help. I am extremely annoyed - DirecTV is fine with taking my money, but the ONLY WAY I could watch my OWN account was to upgrade to 3 streaming devices for more $$$ becuase they have "no idea" how to manage the devices and told me i can NO LONGER do this myself. Is there anyone who knows how to actually fix this (no, changing my user ID and password did not log out the hackers). I haven't been able to log in for weeks and I want a refund.