Too late for FY2005-06 returns?

The FY 2005-06 return is non-taxable, but there was a TDS of 2372 on brokerage income that could be claimed as refund. Does this create an obligation to file a return, or does non-filing of return just mean forgoing the refund ? We do not have the Form 16A issued by the deductor but have other records of tax deducted.