I just want to make you aware of the process of amending finance agreement amounts.
You are able to do this yourself through the orders finance application on V12.
1. Open the finance application
2. Select the Amend Financials button on the left from the list
3. Put in the new amount
4. Hit the APPLY button
5. Ensure Status remains as AGREEMENT RECEIVED. If the status goes back, you would need to hold the magento order until it goes back to AGREEMENT RECEIVED.
6. Once it is at agreement received, you can raise the invoice on the order.
As always if any amendments need to be made AFTER delivery is taken, this is handled by customer service.
I hope this makes sense.