If an extra distance of 50m from existing connections is involved to supply you, that is likely to be at least part of your reason for refusal.
It's likely to be all of the reason for refusal! The install budget is (generously) reckoned to be a thousand quid. I'd reckon that shallow trenching in pavement these days costs around £150 a metre inclusive of all costs from planning through to final reinstatement. Micro trenching only helps a bit, as the digging gangs still need to be mobilised, they still need to work to highway authority standards, they still need proper reinstatement, all that micro trenching saves is some of the materials, which isn't usually enough to make that much difference on a one-off job. If there's existing ducting or other existing access routes that can be used, that dramatically reduces the cost, although any blockages that have to be dug out and cleared will probably be around £150 per blockage site. Anything involving traffic management suddenly jumps up the cost because there's often higher permit costs, plus the costs to hire and setup of lights, signage and barriers - as a broad rule, if there's any need for traffic lights (even if only to temporarily divert a pavement) then a single house installation will not be viable. Under a grass verge costs are probably about £50 a metre, although anything across your own lawn won't cost much as it'll only be a few inches deep (and probably without any effort to do a proper job). Anything involving private land gets complicated quickly, and the legal permissions can take forever and hoover up more of that modest budget. And depending on the local authority, the costs of Section 50 permits for pavement or carriageway works can be significant - some councils are very cheap for small works, some are very expensive in the context of a £1,000 budget - the range appears to be from next to nothing if the council offers an annual or multi-year permit to statutory undertakers, whereas others charge as much as £600 minimum for each job.
If you're desperate and persistent enough, you can agree to pay VM's costs over their standard budget, but you'll need to work hard to get through to the people who will understand and be able to offer you a quote. But based on the indicative figures above, could you afford it?
And in all of this, whilst VM may not be as clear and as helpful as you might like, the underlying issue is not the company's fault or the councils' it's just the generally unfavourable economics of all infrastructure investment. Which is why so many of the early cable companies disappeared, leaving investors out of pocket, as will many of the small "altnet" fibre providers in the coming years, and why most of the early railway investors lost their shirts).
