TAX return not recevied after 4 years

Hi ,

I have filed my return of income for the assessment year 2006-2007 on 25/07/2007 with refund of Rs.33765/ on serial no-1290010892 and submitted in Varanasi  (Range 04).

It is already 3 years and I didn't receive my refund till date.

Can some one help me how to proceed further to  get refund .

Note Till now i have not approach income tax for this retund.

Thanks