External works is a bit of a 'catch all' for all sorts of stuff needs to be done first and it hasn't been, they aren't lying, stuff does have to be done 'externally' before you can be connected up - the problem is actually getting it done.
Frustratingly the people you speak to at VM customer services don't actually know, nor have the ability to find out, what the actual situation is, all of the various stages are outsourced and VM seem to have no insight into what their contractors are actually doing, or not doing. The screen in front of them simply says that x work is due to be done today and, basically that's all they know and can tell you. When and if the contractors fail to actually do it, all, that happens is that an automated system rolls the date on by a day.
As to why VM persist with such an arrangement, I'll leave to the reader to decide?
I believe the current known period for a delayed installation is a little over a year, so you basically have a way to go to make the Guinness Book for Records.
In the meantime, what are you doing for internet access now? Let's be honest, you probably need to be looking at alternative providers now.