Form 'C'

Sir/ Madam,

for e.g. We purchased Rawmaterial from Interstate during 2007-08 (April to June'07)

Supplier Quoted Rs,100 per unit.

My Company not finalised the price because my Customer also not fixing the Final price to us, but we agreed to pay Rs. 80 as adhoc price per unit.

The supplier Invoiced Rs.100 p.unit. with 30days credit.

We accounted & paid for Rs. 80 only p.unit . We gave Form'C' also.

Now (July'08), we fixed the Final price as Rs.90 p.unit

Now, The supplier asking the difference amount and Form 'C' for the differnce amount.

How, I can treat this. please guide me.