The factory that made the 200K extra basically stole them from Kanger and buying them you're buying stolen goods if you want to look at it your way
Kanger will contract a manufacturer to make them X number of widgets for X amount of money. They receive a small pre-production run to verify quality and materials, and if this passes, the manufacturer moves to full production. Kanger then receive their number of widgets for the money, and are happy the contract has been fulfilled to their specifications.
Meanwhile the factory that makes the widgets makes another 200,000 run of them, selling them to FT to distribute. There is no copyright infringement, no intellectual property violated and the materials and supplies (including labor) are all paid by the contracting factory.
Meanwhile, Kanger sell the 'genuine' heads for about $3 a piece. FT sell the almost identical product for about $1.50 a piece. That I know Kanger have no copyright on the designs of their coil heads and FT are not using the word genuine, Kanger or Kanger's logo on either the product or the packaging.
Who is stealing here?