I am getting charged for a phone I never recieved

Back in July I started phone service with XFinity Mobile and ordered a new phone as well. I never received the phone and decided I did not want to use XFinity mobile so I deactivated the line and got a refund on the original down payment. However, I've been charged over $200 in monthly fees since then for a service I don't use. I have contacted customer service for refunds and to get the issue fixed at least 20 times over the last 5 months and am still having issues. If I get charged again I will be hiring a lawyer and taking this to small claims court. Every representative I have spoken with has been incredibly unhelpful, there is clearly a severe lack of communication between the customer service departments and employees.