Please Help: Income Tax Scrutiny

I have received a notice for Income Tax Department on which no section has been mentioned (means under which section this notice is issued) which says " As per 26AS/OLTAS it has been reported that you have entered into a transaction of Rs. XXXXXX during A.Y 2009-10 and it has been further reported that you have not filed your return of income for A.Y 2009-10" but the facts are i have duly filed my Income tax return for the A.Y 2009-10 and it is also appearing in Income tax website and Intimation u/s 143(1) has also been issued and when i deposited the ITR, Compution of the same A.Y as a proof,they directed me to deposit some other documents (Bank statement , Property documents)or in other words they are doing assessment. So what should i do. Please suggest me, urgent