C form in case of purchase returns

Dear All

After searching on this topic, I could understand that in case of purchase returns, C forms are to be issued for net amount.

But the problem is when Goods purchased in One quarter are returned in another quarter.

For e.g.

C form to be issued in Quarter 1 = 90 (Net)

C form to be issued in Quarter 2 = 100.

While issuing C form, the Sales tax department compares C form application amount with the amount shown in return. It does not match in this case. What to do??

Thanks in advance.