How to get refund excess paid income tax for ay 2009-10

I have found out a Demand notice in my income tax efiling e-portal related to AY 2009-10 u/s 1431a.The demand was uploaded by AO , ward no. 58(4), kolkata for Rs.4630/-.I was trying to pay the tax through E-pay tax process through my e-portal using internet banking system of SBI. By mistake i have paid triple amount i.e.Rs.13890/- vide 03 no of challans.The challans are also generated by SBI .So, can anyone help to clear the procedure how to get the balance amount refunded .