If you paid to have your rotating assembly balanced and they did NOT balance your pressure plate you got screwed, blu d and tattooed. If it rotates, in most cases it must be balanced. On race deals I even balance the disc. For a street car I skip the disc to save some bucks unless the customer is willing to pay.
But you had better balance the pressure plate. The good ones are 40-45 grams out and they get worse from there. With the exception being some of the billet CNC covers and pressure plates. They are close, but still must be checked.