Remove NETFLIX charges-I did not ORDER NETFLIX

I had a roommate add Netflix onto my cox bill. The roommate no longer lives in my Home and I do not have access to his Netflix Account. I have called Cox and Netflix numerous times to have this $12.00 a month billing removed but since I do not have the Old Roommates Netflix Account, COX and NETFLIX will not remove charges.  What is my next step??? How can someone who is not on your Cox Bill add Netflix to your Accoun