TDS rate difference

Hi,

My client is having an issue, since we have configured tax codes for a particular vendor at 2% rate and accordingly my client has deducted withholding tax from vendor payment at 2% but actual rate is 10%. Now he is asking us to define new tax code with 10% rate and also he wants us to make adjustment for previous bill TDS difference. Pl. suggest how to adjust deficit deduction.

Thanks in advance