Supersonic, please stay very far away!!!

Please stay very far away from this ISP for your own sanity. Their fibre service is extremely unstable, unreliable, throttled (even though they say it is not). I am trying to stop my service from them with immediate effect, but they say it's not possible!!! Where in your life have you ever heard of such a thing? I can't do my job, I am missing deadlines one after the other, and there is a possibility that I can lose my job because of them. I am on the verge of climbing in my car, take their router and burn it at their reception area. I have never experienced such bad service from any company in my life.