I would stop paymnt on the first check if it is not to late now, and
get bids on making things right . You say he has insurance, well how do
you know, did he present you with proof of insurance, insurance certs
can be changed-forged. You need to talk to his broker and inform them of
your claim. Check with the city for all proper bonding and lisences. A
restraining order will help to show you are serious. Don`t worry about
his collection agency threats, if he is legal, lisenced and insured and
the damages are less than 400 fix things yourself. Get several written
bids for all repairs. If more than 400 for apx 35$ file in small claim
that will shut him up. If he threatens with any thing like a Lien or
anything more you should file small claim anyway to let a judge resolve
the issue. You dont need or want a lawyer for this or small claims. See
if he is completly legal, stop pay, get bids, and file your restraining
order. Hacks like that need the action you are already expecting to do
and have taken. Keep your phone recorder on Auto answer. I had a guy I
stopped payment on and with my auto on recorder I was lucky, because the
first words out of him when I answered were a threat I played back to
the police, without Auto on I would never have had the time to push the
buttons. He is a hack-crook, treat him as one, and keep taking the
first step legally as you have done, to beat him to the punch.