Being charged for a cable box

I’m so upset that I have been calling for over a month about being refunded for cable boxes I don’t have. When I originally set up my services I was giving the option of using the app instead of a box. After turning in the equipment a year ago I have still been being charged for the box. When speaking to multiple representatives they have promised me a credit back and even asking for a card number to refund my money. Each time I call nothing has been done. Either they don’t see a ticket created or nothing.