False demand notice issued to me

hi all,

i hav been issued a demand notice dated 13/06/2012 that the tax that

i hav stated as TDS in m y return is: 72,500

and

the TDS they hav recieved is 11250

aggregate income tax liability is:39342

so they hav asked me to pay 39342-11250= approx 27000 within a month

when i view the form 26AS i see that the total TDS is 72500(approx values) and all are marked (F) which means its been verified

so, pls help me in this regard as they dont wantto pay my refund , the want me to pay further :(( how is this possible

whats the solution