Gemini box logging me into someone else’s account

Box has been working for 6 months.  Yesterday when we turned on TV it logged us into someone else’s account.  I can’t log out since it’s set to auto login and that can only be turned off by logging into the strangers account.  I tried resetting the device but no success.  I called customer service and they walked me through pointless steps.  It’s been escalated but that was days ago - no promised call back.  I called again and was told nothing they could do except escalate again.