Input vat credit reversal

Dear All,

I am a registered dealer in karnataka.

I have purchase chemicals from a dealer in karnataka and subsequently claimed the VAT as input credit in my VAT return but from the (Commercial Tax website) ITC matching report says that the dealer from whom we have purchase has collected the vat from us but did not upload the data nor paid the amount to the department. 

My Question :

a) How to pay back that input vat which i have claimed.

b) What is the interest and penalty for this.

Please any help me out on this.