Construction defect turned cabinets function after mounting

1) When unpacking, the hot / cold Mischhebel no marking blue / red -> can be found in the package, does not lock would be stuck.
2) Scratches in chrome or under the chromium layer, probably happened already in production.

Was then already skeptical, nevertheless mounted because yes as low, but bitter regrets.

After the mounting screw is tightened, the inner workings of the faucet has slipped in the housing down and the mixing lever hot / cold has now contact with the housing and is stiff.