This being a help forum, I'll try and answer your questions accurately and fully.
This is not a serious outfit is it?
Take a look at Virgin Media's Trustpilot page and draw your own conclusions. Or review the regular Ofcom complaints data that regularly has VM at the @rse end of the table.
How are they allowed to get away with this still?
This Kafkaesque comedy for installations has been running continuously for two and half years now, and cost VM millions in lost business, compensation, and complaint adjudication fees. But VM's CEO is more interested in his own hair gel than he is in customer service; With their boss not giving a tinker's cuss, why would his henchman change anything?
Surely a government regulatory body can sanction this joke of a company for this behaviour?
Yes. Ofcom have draconian powers under the Telecommunications Act (2003) but unfortunately Ofcom are also the chocolate teapot amongst regulators and choose to count complaints and do nothing about them. I work for a government regulator, I wouldn't in my wildest nightmares consider working for the badly run, impotent shambles that is Ofcom. Ofcom's bosses have bagged themselves the plushest, vastly expensive offices of any regulator, in a prime position overlooking the Thames. Unfortunately, fancy offices doesn't help improve anything, and having a central London location means they struggle to recruit and retain the high calibre policy, regulation and enforcement professionals that are needed to set, monitor and enforce industry standards. Meanwhile their CEO spins round in the big leather chair, laughing at how much they're being paid without having to do much.
Is there anyone in this organisation that can help?
No. And to offer a more nuanced and detailed answer, no. The regulars of this forum have watched in wonder, horror and despair at how VM have managed the pre-pull (and related re-pull) activity for the past few years. Nobody at VM can help you. Nobody at VM knows anything. Nobody at VM cares. Nobody at VM can cut through the North Korean style bureaucracy. They may be able to offer a hand-wringing apology, and send an email on your behalf to the mythical "area field manager", who in turn is equally unable to help. They can help your raise a complaint that'll be either completely ignored, or get you a poorly worded fob-off that takes you no further forward.
The good news is your pre-installation work could be done without notice tomorrow. The bad news is that the longest known delay reported in this forum was thirteen months. In some cases VM decide after a few weeks it's all too expensive and they cancel the work altogether. But you'll get no advance notice (of any reliability) ahead of those three possible outcomes. The minor and not-really-what-you-want silver lining to the VM cloud is that you're due £5.25 per day for each day between the original installation date and the actual date (or you cancelling in frustration). Even then VM manage to corrode that silver lining by ignorant call centre staff who don't know the regulations or don't care about them and try to browbeat customers into inadequate settlements or nothing at all, or better educated staff who know the regulations but try an weasel out of the obligations, meaning you need to make a formal complaint to VM, reject their resolution and escalate the complaint to industry complaints adjudicator CISAS.
All in all a total **** show. But do a search of this form on the term "Netflix", combine that with your own and others' experience of pre-install, and you'll see that that VM has it's own special sauce that sets it apart from everybody else, and it applies that liberally to everything it does.
Sorry that's not the answers you wanted, but that's how it is.