I've posted about the same thing recently and I'm almost resigned to my install being pushed back from 20-Aug. If that happens, I might have to cancel as I'm currently without broadband and TV after moving house.
It's the complete lack of communication that's the killer. That and the lack of clarity (read: misleading information bordering on lies) about how quickly the install might happen. I ordered in late July and, when I was signing up, was able to select an installation date that was about 5 days in the future. If those dates clearly aren't available, why let people pick them only to reschedule for 5 weeks later. Then they delay installation because the cowboys haven't turned up when they should have.
If I had known better, I wouldn't have signed up and it's the complete lack of customer service that I think is going to lead to me not even starting my contract when they inevitably pee me off this coming week. Awful start to the relationship with customers.