I recently employed a building firm to do some work on my property.
Unfortunately, despite them being recommended and being FMB registered,
they turned out to be cowboys. They didn't turn up for very long, and
hardly worked when they were there. I was busy at work, and so couldn't
keep an eye on them, but my neighbours on either side did. They managed
to turn what should have taken a few days into nearly two weeks.
Eventually, one of them did a ridiculous bodge and tried to pass it off
as okay when asked to put it right. At that point, I asked them to stop
work and not come back. In order to avoid any legal business, I agreed
to pay for what work they'd done. That left a very large job on the
original estimate not done. I was happy to get rid of them - then I got
the invoice

They are basically asking for the majority of the complete figure as
payment. It's over three times what it should be for the work, and not
an inconsiderable amount. They'd not stated what work they were claiming
for, so I wrote back asking them to state the individual work and costs
to justify the amount, saying I'd be happy to pay fair costs. They then
wrote back saying that it was estimated work, and so each job wasn't
recorded, but did list the work. They reiterated their ridiculous sum
was "very fair" despite leaving a very small sum for the work they
didn't do (I've a quote from another builder for the same job they
didn't do, and it's a number of times more).

I'm not sure what to do next. Unfortunately I only got an estimate from
the builders, which was a breakdown of the jobs and a single figure, and
I verbally agreed to the work based on that. If I'd got a proper quote
with the individual jobs itemised I'd not be in this trouble. Lesson
learned.

I'm considering giving my own breakdown of costs, and saying I'd be
willing to pay for that. But I'm pretty sure they'll not accept since
they seem determined to rip me off. Should I just wait to be taken to
court for non-payment and see what happens?

Thanks,
-Duncan