They charging for a service they don't provide

They charging for a service they don't provide. I have a router contract with them, for 3 months now. Since I got it there has been issues. I had internet connection for exactly 1 day and after referring the matter to them they have been of no help whatsoever. They take forever via the customer care line, you hang on for almost an hour and they still can't sort the issue. I sent emails informing them that they should not debit my account until the service is working and they went ahead and deducted anyways. I sent another complaint and to date they have not responded.