Contour TV Billing

I have been a happy Cox customer since June 2010 and that ended in June 2017. This is because I am still being billed for a Contour box I did not want and also returned the same week it was delivered to my house in May of 2017. I have contacted COX on the phone 5 different times and once in-person since June to get this issue fixed and NOTHING has been fixed or refunded even after each rep has said "Yes, we will get this corrected and refunded right away," it still does not change or update my account. Straight up lies each time. My credit card company has already refunded me for some of the months after they did a full month of investigating and resolved the transaction disputes in my favor. I should only be paying about $70 per month for the internet that I have. How do I get this TV service completely removed from my billing and refunded??? Otherwise I will continue to dispute all TV charges with my credit card company, and I SHOULDN'T HAVE TO DO THIS! This is complete nonsense, business carelessness. Next escalation is to talk to the local news.