Have finally managed to get a response from Giganet.
They've now advised me my order was cancelled, so I have to re order and go through another credit check.
Now, what I will say is that at one point I did say that if they couldn't give me a go live date, to cancel my order. But I never actually confirmed a cancellation via email (which they requested) - I even called a few days later to ask for a go live date again, at which point they gave one. At this point, I explicitly said that I don't need it cancelling, and have called many times since asking for updates.
My goodness, getting any clear information from them is an absolute joke - I would say worse than Virgin Media. Nobody seems to have a clue what is going on.