No customer service in the accounts department

How can a company just not respond or resolve customer issues? An unauthorised deduction was made from my account on 12 February 2021. I recieved notices that my service will be suspended because my account was 'in arrears'. I paid an extra month in advance to give time to sort out the issue. Now, mid July, after numerous calls and emails and even a case number CAS-640273-H5N3H7, absolutely no response, no feedback, just a new invoice every month, and still my money is not refunded into my account?!