Removing it after it was returned to them, and restoring it to a standard model as far as possible for maximum resale opportunity, fine. Selling it on to a deal

Removing it after it was returned to them, and restoring it to a standard model as far as possible for maximum resale opportunity, fine. Selling it on to a dealer, including the additional features as part of the package, and then revoking those features them after the sale, is incredibly stupid and sounds illegal.