Tds- whether refund or repay

Hi,

I got the form 16 from my previous company. According to that i have filed the income tax returns. In the form 16 TDS amount was 25042 & same i have entered in the returns. But now i got the mail saying that against my PAN number only 21429 amount has been submitted. & they told me to pay the 3620 amount.

I called to my prev company then the admin person told me that your tax liability comes to 21249 & we have submitted the 25042 & the balance amount 3620 should get refunded.

So now how can i proceed further. I am confused. should i need to again file the returns for the prev years??

Please help

Thanks in advance

Vishal