Complete inability to resolve an issue

I switched to Cool Ideas based on their being voted the best ISP for 2018. I have received shocking service so far, however. They began billing me while I still had service from my previous provider, when the line was not active. Several consultants insisted that it was, until one admitted that the line had not been released. I was billed again before I was able to connect to the internet, despite logging an issue with their account department. It took more than a week for the support people to get the connection to work, so I have paid more than three weeks of service that I did not have. I have sent several emails, called several time, and each time I have to explain the issue again. They keep telling me that my line is active and that I therefore must be billed. No one seems able to investigate the issue and no one is able to respond to repeated queries.