Skyfi's terrible service and lousy product

Skyfi's billing and cancellation systems defy belief. I have been trying to cancel my account with them since 31st July 2017. I am fully paid up (with penalties that they shouldn't have charged), but they are very good at sending threatening letters and rude emails for my account that has been cancelled, and they continue to send more. I have vented my frustrations to Jano Lubbe, the technical manager who promised to resolve my issues, but of course didn't. By the way, their internet service is lousy too, with frequent breaks in connection. Don't touch this company.