Is there any way to cancel the GR with wrong exch rate

Dear All,

I have a question that is there any way to cancel the original Good Receipt(mvt 101) with original posting exchange rate

what was happened like below steps::

1. a user posted GR(currency Euro base, purchase order referred) on 1st Jun
   • but posted with the exchange rate of the previous date since the exchange rate was not yet input at that time
2. finance input correct exchange rate for the date
3. a user cancelled the original GR
   • cancellation posted with special line item, variances
   • Transaction "PRD" Cost (price) differences created on OBYC setting

what will be the answer against the question from finance, "variances are not supposed to happen!".

Is it possible to cancel the GR with its original exchange rate even though the actual exchange rate has been changed

or

the business from finance should accept this nature of SAP?

or

the finance must input the correct exchange rate before the working hour comes?

please help me to solve this issue.

Thanks for your help in advance.