Owning your own home

This is rubbish of course because the scaffolding company is his subcontractor.

This is true in that it's his responsibility if they're his subcontractor, but in reality, nobody wants to fuck with scaffolders so they are a law unto themselves. They are very likely telling the truth about staffing and are just waiting until they need it for another job. Easier to take it down once and move it to the new job than to take it back to the yard, sort it, store it then pull it out again for the next job. It's not going anywhere so they'll just take it as free storage. You can keep asking, but IME it is very unlikely to have any impact. Plus, if the builder has been paid then he has not much of an incentive to piss off the scaffolders. Whatever you do, make sure to check for any damage when they do take it down and report that asap before the builder fucks off over the horizon. Ours smashed up the gutters and fascia boards taking theirs down.