Travails with poor connection from an ISP

I have used Starhub broadband for two decades now, the speed and quality have been poor since day one but I didn't change it as it is tied to the TV subscription which my father used to watch.

Right now, the connection is intermittent. It is unusable unless one uses it to surf, for other activities like gaming, teleconferencing, trading, and anything that requires a constant connection, it is impossible, it has been a week now and Starhub has been unable to resolve it. The service staff is polite and apologetic. What can I do?