Report to the police straightaway. If you give him no premission to replace your pipes and take them away, then he is a thief. Also take this case to the dispute tribunal for his poor workmanship and fraud.
A registered plumber wouldn't risk his plumbing license and career reputation for things like this, so I doubt he is a registered plumber.
Btw copper is worth $7+/kg in scrap metal merchants.作者: alper1 时间: 2012-9-28 00:35:23