It sounds like a new install. Bit odd that they would come do the legwork then not finish the job.
Too many contractors and poor communication between departments - been this way for 20 years now (depending on area perhaps) so doubt it'll get better ;P...
Normally the ground works are what stops installs from happening at a good pace, perhaps the outside bit hasn't actually been completed?
If, assuming new customer, you have enough details to get into your "my virgin media" account then it should show a booking I think - don't quote me on that as new installs might not show up there.
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I do not work for VM, but I would. It is just a Job.
Most things I say I make up and sometimes it's useful, don't be mean if it's wrong.
I would also make websites for them, because the job never seems to require the website to work.