Hold them to their specs, to their agreements, etc. If you see work done that it sub-par, send out emails explaining your analysis and make sure your manager is

Hold them to their specs, to their agreements, etc. If you see work done that it sub-par, send out emails explaining your analysis and make sure your manager is aware. Everything in writing helps. Also take on the mindset that as an employee you're there to own the product. The contractors are temporarily there to help but might not care at all about quality or consequences. You only need to be courteous and professional. You're the customer here, and being upset and complaining if you didn't receive what you bought is expected. You shouldn't be nice and kind to someone who's ripping you off, yet being mean or rude is wrong and counterproductive (unless you're the one who actually hired or is responsible for these contractors in which case it's a judgment call).