Resignation not accepted

I am working in central government. I submitted resignation but the competent authority did not accept my resignation as a case was pending against me for which the investigation is not completed since one year. Around 60 members are involved in the case and due to me there is no revenue loss to the government . Reason for not accepting my resignation cited is investigation is under process.i want to resign and appear for another government job. What are my options now? Should I approach CAT or what to do?