Allegation of bribe for work already completed.

I work as in Income Tax Officer and CBI laid trap and caught my staff red handed while accepting bribe of 10,000/- The complainant registered the complaint alleging that I had demanded bribe through my staff and in FIR also same thing is mentioned but the work for which the alleged bribe was demanded by my staff was already done 15 days prior to the complaint. There is no conversation or voice recording pertaining to me and demand, acceptance and recovery all have been made from the staff only still the CBI are unnecessarily dragging me in the matter. I have the following question: 1) Is non pendency of any official work enough ground for getting the chargesheet quashed u/s 482? 2) When there is no demand, acceptance and recovery from me and also there was no pendency of official work and final order was already delivered to the complainant 15 days prior to her complaint on email, efiling and also through registered letter and the complainant has also accepted the same in his statement then should I move to High Court for quashing the chargesheet u/s 482 or should I move discharge application (although CBI courts rarely discharge any accused)