Although banking and borrowing are final transactions, call
DVC and ask.
Someone may have grabbed the wrong points when you changed your reservation, if I understood it correctly, they may be able to switch the points around.
This did happen to me once and they fixed it.
After all, it's DISNEY, anything is possible, especially if you ask.
What's the worst you'll find out...they can't fix it and you just have to bank them.