Congressman Roy Blunt of Springfield says first-class mail customers should not be subsidizing the cost of competition between the United States Postal Service and the private sector. He’s calling for the United States Postal Rate Commission to freeze rates, not increase them another penny–as the commission is suggesting it might do next year. Blunt says surpluses resulting from present first=class rates are beingused to unfairly compete with companies such as UPS, MAILBOXES, and Federal Express.