[MovedGoalPosts]

Unfortunately just because there is a cabinet nearby doesn't necessarily mean the property itself is serviceable.

In many cases cable needs to be run across property that isn't owned directly by the customer. That can be common parts to blocks of flats, or maybe land of a neighbour. ntl:telewest would need an easement or wayleave for this, which can only be granted by the owner of that land. That's a legal complication that takes time and effort that the cablecos seem to be unwilling to get into for just one customer.

There can be other reasons to, inadequate capacity in the local cabinet, or simply that the under pavement ducts wern't routed near your property. The latter is common for infil developments, or those at the end of small private cul de sacs of two or three houses.