RedOnRed wrote:
The only thing is that there quote is very competitive. For example, I rang
another company yesterday, gave them the measurements over the phone and
they then rang me back with a rough quote for £3000 more then the company
upping their price.

I just don't want to be out of pocket for someone elses oversight. Imagine
me saying there's actually a couple more windows that I forgot to mention.
Well i'd have to pay for those for forgetting to mention them. They've
ballsed up so they should incur the costs.

I think that if they made a genuine mistake, then you should go with
them at their revised price. If there's actually a contract between
you try to compromise. It will cause hard feeling, put yourself in
their shoes. Would you expect the best job from someone willingly
working for you, or at least working without rancour, or someone
you've forced to work for you by means of (legal) threats? If I were
them, and I even had a hint of this sort of stuff going on, I'd drop
the job immediately, regardless. So they've apologised, and offered
to refund your deposit. Sounds fair.