If you believe your advocate deliberately lost your case, especially if you suspect they took money from the opposing party, you may be able to complain. However, simply losing a case, even with good evidence, isn't enough. You'll need to prove the advocate acted against legal procedures or with malicious intent. For cheating specifically, you'd need to prove the elements of cheating as defined by the IPC, which is rare. If you can't prove misconduct, consider appealing with a new advocate, as choosing the right legal representation is ultimately your responsibility.