There is one saying "the mouth of corrupt official is opened only catch hold his nose".
From all this there is one very good thing which u have done is written to vigilance commissioner. But the Vigilance has not taken any proper action. Why don't you make a fresh application under RTI to Vigilance stating
1) day to day progress made on your complaint.
2) officer who is nominated to look into matter.
3) Copies of his findings etc.. if any.Vigilance will take action on the complaint before giving any reply to your application. I think this will serve your purpose.