Sub-standard service from Vox

I am having endless problems with my fibre line. The connection keeps dropping and I am not sure why. If it's not the connection dropping completely, then the speed drops to below 2Mbps on a 20Mbps line. I keep logging a call, then I get someone calling me to say I must switch my router off and on again (it feels like they are wishing I would stop calling to complain). I keep doing the same old thing and still I am having to live with the same old unreliable fibre connection. The one night there was an area outage, and the guys from Vox were quick to shrug me off by indicating this reason to me. They haven't considered the fact that numerous calls were logged by me complaining about my unstable connection before the area outage. Vox used to be a very good service provider and I have been with them for a few years now, but recently it just seems that they keep dropping the ball and make no attempt to pick it up. I have logged another call today and usually they call me back the same day, but I feel they are now trying to wish me away. I rely on my internet connection because I work from home, and I am now being made to feel like I need to accept this substandard service. Vox, I need to work to pay my account where the amounts due doesn't drop like my connectivity. Please sort this out asap. I am not happy.