how can I get my money back with out a baraclava and a dark night?
have you tried asking him?
the usual route is to make clear that you are not happy with his work and then give
him chance to either personally rectify or for him to pay somebody to rectify his work.
failing this, you can follow the legal route, i.e. direct to small claims court or inform the builder that you intend having the work rectified and that he the dodgy builder shall foot the bill.
it is back to small claims though if he does not agree to pay.
you could also go down the
other route.