The US Supreme Court yesterday refused to hear the appeal of the criminal convictions of Adelphia Communications founder John Rigas and his son, Timothy, who had been the cable company’s CFO. The high court let stand a ruling by a federal appeals court in New York last year that upheld their convictions on charges of securities fraud, bank fraud and conspiracy to commit bank fraud. John Rigas, 83, is currently serving a 15-year term in federal prison and Timothy a 20-year term. Prosecutors had claimed that the Rigas family used Adelphia as a piggy bank to fund their own projects and hid nearly 2.3 billion in debt from shareholders. The company’s cable systems were sold off by a federal bankruptcy court.