Don't be so dramatic. If the Sky is stopping your broadband from working and the Sky installer did it, tell them in no uncertain terms and they will be out to fix it. Just don't be fobbed off, make sure an engineer calls FOR FREE and they fix it before they leave. They are not providing their service as has been mentioned which means that their contract with you isn't valid. They can't make you pay £30 a month and if you cancel because of breach of contract then you won't be liable either. Just make sure you explain to them that it is their fault your broadband is not working properly.