Intimation us 143 (1)

CHAITRI SUDHAKARBHAI KHAROD (ARTICLE) (752 Points)

16 January 2020  
in A.y. 2010-11, my father got intimation us 143 (1) for demand of tds due to mismatch of PAN...I responded it but now I received mail that your return has not been filed or processed...so for further clarification contact your jurisdictional AO....

Please explain me why such mail I received and now what should I do? ?