Cda demand

One of my client has recd notice in Form 604A (based on findings of CDA) for Fin. Year 2011-12 asking for/showing balance payment of MVAT Rs.390/-.

Total MVAT collected on Sales was Rs.42080/- & Total MVAT paid on Purchases was Rs. 40140/-. Hence, balance sum of Rs. 1940/- was paid at the time of filing of returns.

Now, as client has told to pay this demand of Rs.390/- alongwith interest, how much interest will be payable U/S.30 (2) & 30 (4).

T & R

KP