Pure internet horror and worst service ever.

I've been an Afrihost customer for nearly a decade and would always recommend them to others for their excellent service. Until I gave up my ADSL package with them and moved to fibre a few months ago. Since then I've had an unstable line and hardly get 1Mbps on the 20Mbps line. I keep logging calls and then get no call back from their service centre. When I do get hold of them, I am told to switch off my router for 15 minutes and switch on again. Twice they've changed the settings on my router and service is now worse. This morning I phoned and asked to speak to a supervisor, to be told there is NO supervisor on duty. I logged a call and two and a half hours later still no call back. I can't even stream radio or audio on this 20Mbps line. I get no refund for this ****ty service. And even no response on Twitter. Twice I asked Afrihost on Facebook who I can speak to to get feedback on the terrible service, but also NO reply on Facebook. I've even asked to speak to Gian, the mysterious Afrihost boss, but got no feedback. This is pure internet horror.